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2022-04-13serial: samsung_tty: do not unlock port->lock for uart_write_wakeup()Jiri Slaby1-4/+1
[ Upstream commit 988c7c00691008ea1daaa1235680a0da49dab4e8 ] The commit c15c3747ee32 (serial: samsung: fix potential soft lockup during uart write) added an unlock of port->lock before uart_write_wakeup() and a lock after it. It was always problematic to write data from tty_ldisc_ops::write_wakeup and it was even documented that way. We fixed the line disciplines to conform to this recently. So if there is still a missed one, we should fix them instead of this workaround. On the top of that, s3c24xx_serial_tx_dma_complete() in this driver still holds the port->lock while calling uart_write_wakeup(). So revert the wrap added by the commit above. Cc: Thomas Abraham <thomas.abraham@linaro.org> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Hyeonkook Kim <hk619.kim@samsung.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220308115153.4225-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08serial: 8250: fix XOFF/XON sending when DMA is usedIlpo Järvinen3-4/+25
[ Upstream commit f58c252e30cf74f68b0054293adc03b5923b9f0e ] When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly. Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper. The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f165f (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all). Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz <gilles.buloz@kontron.com> Tested-by: Gilles Buloz <gilles.buloz@kontron.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08kgdboc: fix return value of __setup handlerRandy Dunlap1-3/+3
[ Upstream commit ab818c7aa7544bf8d2dd4bdf68878b17a02eb332 ] __setup() handlers should return 1 to obsolete_checksetup() in init/main.c to indicate that the boot option has been handled. A return of 0 causes the boot option/value to be listed as an Unknown kernel parameter and added to init's (limited) environment strings. So return 1 from kgdboc_option_setup(). Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc7 kgdboc=kbd kgdbts=", will be passed to user space. Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc7 kgdboc=kbd kgdbts= Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Fixes: 1bd54d851f50 ("kgdboc: Passing ekgdboc to command line causes panic") Fixes: f2d937f3bf00 ("consoles: polling support, kgdboc") Cc: He Zhe <zhe.he@windriver.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: kgdb-bugreport@lists.sourceforge.net Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: linux-serial@vger.kernel.org Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220309033018.17936-1-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08serial: 8250: Fix race condition in RTS-after-send handlingUwe Kleine-König1-0/+12
[ Upstream commit dedab69fd650ea74710b2e626e63fd35584ef773 ] Set em485->active_timer = NULL isn't always enough to take out the stop timer. While there is a check that it acts in the right state (i.e. waiting for RTS-after-send to pass after sending some chars) but the following might happen: - CPU1: some chars send, shifter becomes empty, stop tx timer armed - CPU0: more chars send before RTS-after-send expired - CPU0: shifter empty irq, port lock taken - CPU1: tx timer triggers, waits for port lock - CPU0: em485->active_timer = &em485->stop_tx_timer, hrtimer_start(), releases lock() - CPU1: get lock, see em485->active_timer == &em485->stop_tx_timer, tear down RTS too early This fix bases on research done by Steffen Trumtrar. Fixes: b86f86e8e7c5 ("serial: 8250: fix potential deadlock in rs485-mode") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220215160236.344236-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08serial: 8250_lpss: Balance reference count for PCI DMA deviceAndy Shevchenko1-6/+22
[ Upstream commit 5318f70da7e82649d794fc27d8a127c22aa3566e ] The pci_get_slot() increases its reference count, the caller must decrement the reference count by calling pci_dev_put(). Fixes: 9a1870ce812e ("serial: 8250: don't use slave_id of dma_slave_config") Depends-on: a13e19cf3dc1 ("serial: 8250_lpss: split LPSS driver to separate module") Reported-by: Qing Wang <wangqing@vivo.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220223151240.70248-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08serial: 8250_mid: Balance reference count for PCI DMA deviceAndy Shevchenko1-4/+15
[ Upstream commit 67ec6dd0b257bd81b4e9fcac89b29da72f6265e5 ] The pci_get_slot() increases its reference count, the caller must decrement the reference count by calling pci_dev_put(). Fixes: 90b9aacf912a ("serial: 8250_pci: add Intel Tangier support") Fixes: f549e94effa1 ("serial: 8250_pci: add Intel Penwell ports") Reported-by: Qing Wang <wangqing@vivo.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Depends-on: d9eda9bab237 ("serial: 8250_pci: Intel MID UART support to its own driver") Link: https://lore.kernel.org/r/20220215100920.41984-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08serial: 8250_aspeed_vuart: add PORT_ASPEED_VUART port typeZev Weiss2-1/+9
[ Upstream commit a603ca60cebff8589882427a67f870ed946b3fc8 ] Commit 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping") fixed a bug that had, as a side-effect, prevented the 8250_aspeed_vuart driver from enabling the VUART's FIFOs. However, fixing that (and hence enabling the FIFOs) has in turn revealed what appears to be a hardware bug in the ASPEED VUART in which the host-side THRE bit doesn't get if the BMC-side receive FIFO trigger level is set to anything but one byte. This causes problems for polled-mode writes from the host -- for example, Linux kernel console writes proceed at a glacial pace (less than 100 bytes per second) because the write path waits for a 10ms timeout to expire after every character instead of being able to continue on to the next character upon seeing THRE asserted. (GRUB behaves similarly.) As a workaround, introduce a new port type for the ASPEED VUART that's identical to PORT_16550A as it had previously been using, but with UART_FCR_R_TRIG_00 instead to set the receive FIFO trigger level to one byte, which (experimentally) seems to avoid the problematic THRE behavior. Fixes: 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping") Tested-by: Konstantin Aladyshev <aladyshev22@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Zev Weiss <zev@bewilderbeest.net> Link: https://lore.kernel.org/r/20220211004203.14915-1-zev@bewilderbeest.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08serial: stm32: prevent TDR register overwrite when sending x_charValentin Caron1-0/+12
[ Upstream commit d3d079bde07e1b7deaeb57506dc0b86010121d17 ] When sending x_char in stm32_usart_transmit_chars(), driver can overwrite the value of TDR register by the value of x_char. If this happens, the previous value that was present in TDR register will not be sent through uart. This code checks if the previous value in TDR register is sent before writing the x_char value into register. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable <stable@vger.kernel.org> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220111164441.6178-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-02sc16is7xx: Fix for incorrect data being transmittedPhil Elwell1-0/+3
commit eebb0f4e894f1e9577a56b337693d1051dd6ebfd upstream. UART drivers are meant to use the port spinlock within certain methods, to protect against reentrancy. The sc16is7xx driver does very little locking, presumably because when added it triggers "scheduling while atomic" errors. This is due to the use of mutexes within the regmap abstraction layer, and the mutex implementation's habit of sleeping the current thread while waiting for access. Unfortunately this lack of interlocking can lead to corruption of outbound data, which occurs when the buffer used for I2C transmission is used simultaneously by two threads - a work queue thread running sc16is7xx_tx_proc, and an IRQ thread in sc16is7xx_port_irq, both of which can call sc16is7xx_handle_tx. An earlier patch added efr_lock, a mutex that controls access to the EFR register. This mutex is already claimed in the IRQ handler, and all that is required is to claim the same mutex in sc16is7xx_tx_proc. See: https://github.com/raspberrypi/linux/issues/4885 Fixes: 6393ff1c4435 ("sc16is7xx: Use threaded IRQ") Cc: stable <stable@vger.kernel.org> Signed-off-by: Phil Elwell <phil@raspberrypi.com> Link: https://lore.kernel.org/r/20220216160802.1026013-1-phil@raspberrypi.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-23serial: parisc: GSC: fix build when IOSAPIC is not setRandy Dunlap1-1/+1
commit 6e8793674bb0d1135ca0e5c9f7e16fecbf815926 upstream. There is a build error when using a kernel .config file from 'kernel test robot' for a different build problem: hppa64-linux-ld: drivers/tty/serial/8250/8250_gsc.o: in function `.LC3': (.data.rel.ro+0x18): undefined reference to `iosapic_serial_irq' when: CONFIG_GSC=y CONFIG_SERIO_GSCPS2=y CONFIG_SERIAL_8250_GSC=y CONFIG_PCI is not set and hence PCI_LBA is not set. IOSAPIC depends on PCI_LBA, so IOSAPIC is not set/enabled. Make the use of iosapic_serial_irq() conditional to fix the build error. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Johan Hovold <johan@kernel.org> Suggested-by: Helge Deller <deller@gmx.de> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01tty: Add support for Brainboxes UC cards.Cameron Williams1-2/+98
commit 152d1afa834c84530828ee031cf07a00e0fc0b8c upstream. This commit adds support for the some of the Brainboxes PCI range of cards, including the UC-101, UC-235/246, UC-257, UC-268, UC-275/279, UC-302, UC-310, UC-313, UC-320/324, UC-346, UC-357, UC-368 and UC-420/431. Signed-off-by: Cameron Williams <cang1@live.co.uk> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/AM5PR0202MB2564688493F7DD9B9C610827C45E9@AM5PR0202MB2564.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01serial: stm32: fix software flow control transferValentin Caron1-1/+1
commit 037b91ec7729524107982e36ec4b40f9b174f7a2 upstream. x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty. Fix start_tx condition to allow x_char to be sent. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable <stable@vger.kernel.org> Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01serial: 8250: of: Fix mapped region size when using reg-offset propertyRobert Hancock1-1/+10
commit d06b1cf28297e27127d3da54753a3a01a2fa2f28 upstream. 8250_of supports a reg-offset property which is intended to handle cases where the device registers start at an offset inside the region of memory allocated to the device. The Xilinx 16550 UART, for which this support was initially added, requires this. However, the code did not adjust the overall size of the mapped region accordingly, causing the driver to request an area of memory past the end of the device's allocation. For example, if the UART was allocated an address of 0xb0130000, size of 0x10000 and reg-offset of 0x1000 in the device tree, the region of memory reserved was b0131000-b0140fff, which caused the driver for the region starting at b0140000 to fail to probe. Fix this by subtracting reg-offset from the mapped region size. Fixes: b912b5e2cfb3 ([POWERPC] Xilinx: of_serial support for Xilinx uart 16550.) Cc: stable <stable@vger.kernel.org> Signed-off-by: Robert Hancock <robert.hancock@calian.com> Link: https://lore.kernel.org/r/20220112194214.881844-1-robert.hancock@calian.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrlJochen Mades1-2/+6
commit 62f676ff7898f6c1bd26ce014564773a3dc00601 upstream. Commit 8d479237727c ("serial: amba-pl011: add RS485 support") sought to keep RTS deasserted on set_mctrl if rs485 is enabled. However it did so only if deasserted RTS polarity is high. Fix it in case it's low. Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support") Cc: stable@vger.kernel.org # v5.15+ Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Jochen Mades <jochen@mades.net> [lukas: copyedit commit message, add stable designation] Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/85fa3323ba8c307943969b7343e23f34c3e652ba.1642909284.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27serial: Fix incorrect rs485 polarity on uart openLukas Wunner1-2/+2
commit d3b3404df318504ec084213ab1065b73f49b0f1d upstream. Commit a6845e1e1b78 ("serial: core: Consider rs485 settings to drive RTS") sought to deassert RTS when opening an rs485-enabled uart port. That way, the transceiver does not occupy the bus until it transmits data. Unfortunately, the commit mixed up the logic and *asserted* RTS instead of *deasserting* it: The commit amended uart_port_dtr_rts(), which raises DTR and RTS when opening an rs232 port. "Raising" actually means lowering the signal that's coming out of the uart, because an rs232 transceiver not only changes a signal's voltage level, it also *inverts* the signal. See the simplified schematic in the MAX232 datasheet for an example: https://www.ti.com/lit/ds/symlink/max232.pdf So, to raise RTS on an rs232 port, TIOCM_RTS is *set* in port->mctrl and that results in the signal being driven low. In contrast to rs232, the signal level for rs485 Transmit Enable is the identity, not the inversion: If the transceiver expects a "high" RTS signal for Transmit Enable, the signal coming out of the uart must also be high, so TIOCM_RTS must be *cleared* in port->mctrl. The commit did the exact opposite, but it's easy to see why given the confusing semantics of rs232 and rs485. Fix it. Fixes: a6845e1e1b78 ("serial: core: Consider rs485 settings to drive RTS") Cc: stable@vger.kernel.org # v4.14+ Cc: Rafael Gago Castano <rgc@hms.se> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/9395767847833f2f3193c49cde38501eeb3b5669.1639821059.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27serial: core: Keep mctrl register state and cached copy in syncLukas Wunner1-1/+2
[ Upstream commit 93a770b7e16772530196674ffc79bb13fa927dc6 ] struct uart_port contains a cached copy of the Modem Control signals. It is used to skip register writes in uart_update_mctrl() if the new signal state equals the old signal state. It also avoids a register read to obtain the current state of output signals. When a uart_port is registered, uart_configure_port() changes signal state but neglects to keep the cached copy in sync. That may cause a subsequent register write to be incorrectly skipped. Fix it before it trips somebody up. This behavior has been present ever since the serial core was introduced in 2002: https://git.kernel.org/history/history/c/33c0d1b0c3eb So far it was never an issue because the cached copy is initialized to 0 by kzalloc() and when uart_configure_port() is executed, at most DTR has been set by uart_set_options() or sunsu_console_setup(). Therefore, a stable designation seems unnecessary. Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/bceeaba030b028ed810272d55d5fc6f3656ddddb.1641129752.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: pl011: Drop CR register reset on set_termiosLukas Wunner1-2/+0
[ Upstream commit e368cc656fd6d0075f1c3ab9676e2001451e3e04 ] pl011_set_termios() briefly resets the CR register to zero, thereby glitching DTR/RTS signals. With rs485 this may result in the bus being occupied for no reason. Where does this register write originate from? The PL011 driver was forked from the PL010 driver in 2004: https://git.kernel.org/history/history/c/157c0342e591 Until this commit, the PL010 driver's IRQ handler ambauart_int() modified the CR register without holding the port spinlock. ambauart_set_termios() also modified that register. To prevent concurrent read-modify-writes by the IRQ handler and to prevent transmission while changing baudrate, ambauart_set_termios() had to disable interrupts. On the PL010, that is achieved by writing zero to the CR register. However, on the PL011, interrupts are disabled in the IMSC register, not in the CR register. Additionally, the commit amended both the PL010 and PL011 driver to acquire the port spinlock in the IRQ handler, obviating the need to disable interrupts in ->set_termios(). So the CR register write is obsolete for two reasons. Drop it. Cc: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/f49f945375f5ccb979893c49f1129f51651ac738.1641129062.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: pl010: Drop CR register reset on set_termiosLukas Wunner1-3/+0
[ Upstream commit 08a0c6dff91c965e39905cf200d22db989203ccb ] pl010_set_termios() briefly resets the CR register to zero. Where does this register write come from? The PL010 driver's IRQ handler ambauart_int() originally modified the CR register without holding the port spinlock. ambauart_set_termios() also modified that register. To prevent concurrent read-modify-writes by the IRQ handler and to prevent transmission while changing baudrate, ambauart_set_termios() had to disable interrupts. That is achieved by writing zero to the CR register. However in 2004 the PL010 driver was amended to acquire the port spinlock in the IRQ handler, obviating the need to disable interrupts in ->set_termios(): https://git.kernel.org/history/history/c/157c0342e591 That rendered the CR register write obsolete. Drop it. Cc: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/fcaff16e5b1abb4cc3da5a2879ac13f278b99ed0.1641128728.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: imx: disable UCR4_OREN in .stop_rx() instead of .shutdown()Fugang Duan1-2/+5
[ Upstream commit 028e083832b06fdeeb290e1e57dc1f6702c4c215 ] The UCR4_OREN should be disabled before disabling the uart receiver in .stop_rx() instead of in the .shutdown(). Otherwise, if we have the overrun error during the receiver disable process, the overrun interrupt will keep trigging until we disable the OREN interrupt in the .shutdown(), because the ORE status can only be cleared when read the rx FIFO or reset the controller. Although the called time between the receiver disable and OREN disable in .shutdown() is very short, there is still the risk of endless interrupt during this short period of time. So here change to disable OREN before the receiver been disabled in .stop_rx(). Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20211125020349.4980-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: stm32: move tx dma terminate DMA to shutdownValentin Caron1-1/+5
[ Upstream commit 56a23f9319e86e1d62a109896e2c7e52c414e67d ] Terminate DMA transaction and clear CR3_DMAT when shutdown is requested, instead of when remove is requested. If DMA transfer is not stopped in shutdown ops, driver will fail to start a new DMA transfer after next startup ops. Fixes: 3489187204eb ("serial: stm32: adding dma support") Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220104182445.4195-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: liteuart: fix MODULE_ALIASAlyssa Ross1-1/+1
[ Upstream commit 556172fabd226ba14b70c1740d0826a4717473dc ] modprobe can't handle spaces in aliases. Fixes: 1da81e5562fa ("drivers/tty/serial: add LiteUART driver") Signed-off-by: Alyssa Ross <hi@alyssa.is> Link: https://lore.kernel.org/r/20220104131030.1674733-1-hi@alyssa.is Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: 8250_bcm7271: Propagate error codes from brcmuart_probe()Lad Prabhakar1-3/+8
[ Upstream commit c195438f1e84de8fa46b4f5264d12379bee6e9a1 ] In case of failures brcmuart_probe() always returned -ENODEV, this isn't correct for example platform_get_irq_byname() may return -EPROBE_DEFER to handle such cases propagate error codes in brcmuart_probe() in case of failures. Fixes: 41a469482de25 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20211224142917.6966-4-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: amba-pl011: do not request memory region twiceLino Sanfilippo1-24/+3
[ Upstream commit d1180405c7b5c7a1c6bde79d5fc24fe931430737 ] With commit 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()") the function devm_ioremap() called from pl011_setup_port() was replaced with devm_ioremap_resource(). Since this function not only remaps but also requests the ports io memory region it now collides with the .config_port() callback which requests the same region at uart port registration. Since devm_ioremap_resource() already claims the memory successfully, the request in .config_port() fails. Later at uart port deregistration the attempt to release the unclaimed memory also fails. The failure results in a “Trying to free nonexistent resource" warning. Fix these issues by removing the callbacks that implement the redundant memory allocation/release. Also make sure that changing the drivers io memory base address via TIOCSSERIAL is not allowed any more. Fixes: 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()") Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Link: https://lore.kernel.org/r/20211129174238.8333-1-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: uartlite: allow 64 bit addressLizhi Hou1-1/+1
[ Upstream commit 3672fb65155530b5eea6225685c75329b6debec3 ] The base address of uartlite registers could be 64 bit address which is from device resource. When ulite_probe() calls ulite_assign(), this 64 bit address is casted to 32-bit. The fix is to replace "u32" type with "phys_addr_t" type for the base address in ulite_assign() argument list. Fixes: 8fa7b6100693 ("[POWERPC] Uartlite: Separate the bus binding from the driver proper") Signed-off-by: Lizhi Hou <lizhi.hou@xilinx.com> Link: https://lore.kernel.org/r/20211129202302.1319033-1-lizhi.hou@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: atmel: Call dma_async_issue_pending()Tudor Ambarus1-0/+4
[ Upstream commit 4f4b9b5895614eb2e2b5f4cab7858f44bd113e1b ] The driver wrongly assummed that tx_submit() will start the transfer, which is not the case, now that the at_xdmac driver is fixed. tx_submit is supposed to push the current transaction descriptor to a pending queue, waiting for issue_pending to be called. issue_pending must start the transfer, not tx_submit. Fixes: 34df42f59a60 ("serial: at91: add rx dma support") Fixes: 08f738be88bb ("serial: at91: add tx dma support") Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Link: https://lore.kernel.org/r/20211125090028.786832-4-tudor.ambarus@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: atmel: Check return code of dmaengine_submit()Tudor Ambarus1-0/+10
[ Upstream commit 1e67bd2b8cb90b66e89562598e9c2046246832d3 ] The tx_submit() method of struct dma_async_tx_descriptor is entitled to do sanity checks and return errors if encountered. It's not the case for the DMA controller drivers that this client is using (at_h/xdmac), because they currently don't do sanity checks and always return a positive cookie at tx_submit() method. In case the controller drivers will implement sanity checks and return errors, print a message so that the client will be informed that something went wrong at tx_submit() level. Fixes: 08f738be88bb ("serial: at91: add tx dma support") Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Link: https://lore.kernel.org/r/20211125090028.786832-3-tudor.ambarus@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22serial: 8250_fintek: Fix garbled text for consoleJi-Ze Hong (Peter Hong)1-20/+0
commit 6c33ff728812aa18792afffaf2c9873b898e7512 upstream. Commit fab8a02b73eb ("serial: 8250_fintek: Enable high speed mode on Fintek F81866") introduced support to use high baudrate with Fintek SuperIO UARTs. It'll change clocksources when the UART probed. But when user add kernel parameter "console=ttyS0,115200 console=tty0" to make the UART as console output, the console will output garbled text after the following kernel message. [ 3.681188] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled The issue is occurs in following step: probe_setup_port() -> fintek_8250_goto_highspeed() It change clocksource from 115200 to 921600 with wrong time, it should change clocksource in set_termios() not in probed. The following 3 patches are implemented change clocksource in fintek_8250_set_termios(). Commit 58178914ae5b ("serial: 8250_fintek: UART dynamic clocksource on Fintek F81216H") Commit 195638b6d44f ("serial: 8250_fintek: UART dynamic clocksource on Fintek F81866") Commit 423d9118c624 ("serial: 8250_fintek: Add F81966 Support") Due to the high baud rate had implemented above 3 patches and the patch Commit fab8a02b73eb ("serial: 8250_fintek: Enable high speed mode on Fintek F81866") is bugged, So this patch will remove it. Fixes: fab8a02b73eb ("serial: 8250_fintek: Enable high speed mode on Fintek F81866") Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com> Link: https://lore.kernel.org/r/20211215075835.2072-1-hpeter+linux_kernel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17Revert "tty: serial: fsl_lpuart: drop earlycon entry for i.MX8QXP"Alexander Stein1-0/+1
[ Upstream commit 4e9679738a918d8a482ac6a2cb2bb871f094bb84 ] Revert commit b4b844930f27 ("tty: serial: fsl_lpuart: drop earlycon entry for i.MX8QXP"), because this breaks earlycon support on imx8qm/imx8qxp. While it is true that for earlycon there is no difference between i.MX8QXP and i.MX7ULP (for now at least), there are differences regarding clocks and fixups for wakeup support. For that reason it was deemed unacceptable to add the imx7ulp compatible to device tree in order to get earlycon working again. Reviewed-by: Peng Fan <peng.fan@nxp.com> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> Link: https://lore.kernel.org/r/20211124073109.805088-1-alexander.stein@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08serial: liteuart: fix minor-number leak on probe errorsJohan Hovold1-3/+14
commit dd5e90b16cca8a697cbe17b72e2a5f49291cabb2 upstream. Make sure to release the allocated minor number before returning on probe errors. Fixes: 1da81e5562fa ("drivers/tty/serial: add LiteUART driver") Cc: stable@vger.kernel.org # 5.11 Cc: Filip Kokosinski <fkokosinski@antmicro.com> Cc: Mateusz Holenko <mholenko@antmicro.com> Reviewed-by: Stafford Horne <shorne@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211117100512.5058-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: liteuart: fix use-after-free and memleak on unbindJohan Hovold1-0/+1
commit 05f929b395dec8957b636ff14e66b277ed022ed9 upstream. Deregister the port when unbinding the driver to prevent it from being used after releasing the driver data and leaking memory allocated by serial core. Fixes: 1da81e5562fa ("drivers/tty/serial: add LiteUART driver") Cc: stable@vger.kernel.org # 5.11 Cc: Filip Kokosinski <fkokosinski@antmicro.com> Cc: Mateusz Holenko <mholenko@antmicro.com> Reviewed-by: Stafford Horne <shorne@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211117100512.5058-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: liteuart: Fix NULL pointer dereference in ->remove()Ilia Sergachev1-0/+2
commit 0f55f89d98c8b3e12b4f55f71c127a173e29557c upstream. drvdata has to be set in _probe() - otherwise platform_get_drvdata() causes null pointer dereference BUG in _remove(). Fixes: 1da81e5562fa ("drivers/tty/serial: add LiteUART driver") Cc: stable <stable@vger.kernel.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Ilia Sergachev <silia@ethz.ch> Link: https://lore.kernel.org/r/20211115224944.23f8c12b@dtkw Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250: Fix RTS modem control while in rs485 modeLukas Wunner2-7/+5
commit f85e04503f369b3f2be28c83fc48b74e19936ebc upstream. Commit f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") sought to prevent user space from interfering with rs485 communication by ignoring a TIOCMSET ioctl() which changes RTS polarity. It did so in serial8250_do_set_mctrl(), which turns out to be too deep in the call stack: When a uart_port is opened, RTS polarity is set by the rs485-aware function uart_port_dtr_rts(). It calls down to serial8250_do_set_mctrl() and that particular RTS polarity change should *not* be ignored. The user-visible result is that on 8250_omap ports which use rs485 with inverse polarity (RTS bit in MCR register is 1 to receive, 0 to send), a newly opened port initially sets up RTS for sending instead of receiving. That's because omap_8250_startup() sets the cached value up->mcr to 0 and omap_8250_restore_regs() subsequently writes it to the MCR register. Due to the commit, serial8250_do_set_mctrl() preserves that incorrect register value: do_sys_openat2 do_filp_open path_openat vfs_open do_dentry_open chrdev_open tty_open uart_open tty_port_open uart_port_activate uart_startup uart_port_startup serial8250_startup omap_8250_startup # up->mcr = 0 uart_change_speed serial8250_set_termios omap_8250_set_termios omap_8250_restore_regs serial8250_out_MCR # up->mcr written tty_port_block_til_ready uart_dtr_rts uart_port_dtr_rts serial8250_set_mctrl omap8250_set_mctrl serial8250_do_set_mctrl # mcr[1] = 1 ignored Fix by intercepting RTS changes from user space in uart_tiocmset() instead. Link: https://lore.kernel.org/linux-serial/20211027111644.1996921-1-baocheng.su@siemens.com/ Fixes: f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") Cc: Chao Zeng <chao.zeng@siemens.com> Cc: stable@vger.kernel.org # v5.7+ Reported-by: Su Bao Cheng <baocheng.su@siemens.com> Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Tested-by: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/21170e622a1aaf842a50b32146008b5374b3dd1d.1637596432.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250_pci: rewrite pericom_do_set_divisor()Jay Dolan1-13/+17
commit bb1201d4b38ec67bd9a871cf86b0cc10f28b15b5 upstream. Have pericom_do_set_divisor() use the uartclk instead of a hard coded value to work with different speed crystals. Tested with 14.7456 and 24 MHz crystals. Have pericom_do_set_divisor() always calculate the divisor rather than call serial8250_do_set_divisor() for rates below baud_base. Do not write registers or call serial8250_do_set_divisor() if valid divisors could not be found. Fixes: 6bf4e42f1d19 ("serial: 8250: Add support for higher baud rates to Pericom chips") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211122120604.3909-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250_pci: Fix ACCES entries in pci_serial_quirks arrayJay Dolan1-1/+8
commit c525c5d2437f93520388920baac6d9340c65d239 upstream. Fix error in table for PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S that caused it and PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4 to be missing their fourth port. Fixes: 78d3820b9bd3 ("serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 chip use the pci_pericom_setup()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211122120604.3909-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: core: fix transmit-buffer reset and memleakJohan Hovold1-1/+12
commit 00de977f9e0aa9760d9a79d1e41ff780f74e3424 upstream. Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close. Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted. Furthermore, the buffer of any port that has been opened would leak on driver unbind. Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()"). Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace ("tty/serial: do not free trasnmit buffer page under port lock")). Link: https://lore.kernel.org/r/319321886d97c456203d5c6a576a5480d07c3478.1635781688.git.baruch@tkos.co.il Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Cc: stable@vger.kernel.org # 4.9 Cc: Rob Herring <robh@kernel.org> Reported-by: Baruch Siach <baruch@tkos.co.il> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211108085431.12637-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: tegra: Change lower tolerance baud rate limit for tegra20 and tegra30Patrik John1-2/+2
commit b40de7469ef135161c80af0e8c462298cc5dac00 upstream. The current implementation uses 0 as lower limit for the baud rate tolerance for tegra20 and tegra30 chips which causes isses on UART initialization as soon as baud rate clock is lower than required even when within the standard UART tolerance of +/- 4%. This fix aligns the implementation with the initial commit description of +/- 4% tolerance for tegra chips other than tegra186 and tegra194. Fixes: d781ec21bae6 ("serial: tegra: report clk rate errors") Cc: stable <stable@vger.kernel.org> Signed-off-by: Patrik John <patrik.john@u-blox.com> Link: https://lore.kernel.org/r/sig.19614244f8.20211123132737.88341-1-patrik.john@u-blox.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: pl011: Add ACPI SBSA UART match idPierre Gondois1-0/+1
commit ac442a077acf9a6bf1db4320ec0c3f303be092b3 upstream. The document 'ACPI for Arm Components 1.0' defines the following _HID mappings: -'Prime cell UART (PL011)': ARMH0011 -'SBSA UART': ARMHB000 Use the sbsa-uart driver when a device is described with the 'ARMHB000' _HID. Note: PL011 devices currently use the sbsa-uart driver instead of the uart-pl011 driver. Indeed, PL011 devices are not bound to a clock in ACPI. It is not possible to change their baudrate. Cc: <stable@vger.kernel.org> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Link: https://lore.kernel.org/r/20211109172248.19061-1-Pierre.Gondois@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08tty: serial: msm_serial: Deactivate RX DMA for polling supportSven Eckelmann1-0/+3
commit 7492ffc90fa126afb67d4392d56cb4134780194a upstream. The CONSOLE_POLLING mode is used for tools like k(g)db. In this kind of setup, it is often sharing a serial device with the normal system console. This is usually no problem because the polling helpers can consume input values directly (when in kgdb context) and the normal Linux handlers can only consume new input values after kgdb switched back. This is not true anymore when RX DMA is enabled for UARTDM controllers. Single input values can no longer be received correctly. Instead following seems to happen: * on 1. input, some old input is read (continuously) * on 2. input, two old inputs are read (continuously) * on 3. input, three old input values are read (continuously) * on 4. input, 4 previous inputs are received This repeats then for each group of 4 input values. This behavior changes slightly depending on what state the controller was when the first input was received. But this makes working with kgdb basically impossible because control messages are always corrupted when kgdboc tries to parse them. RX DMA should therefore be off when CONSOLE_POLLING is enabled to avoid these kind of problems. No such problem was noticed for TX DMA. Fixes: 99693945013a ("tty: serial: msm: Add RX DMA support") Cc: stable@vger.kernel.org Signed-off-by: Sven Eckelmann <sven@narfation.org> Link: https://lore.kernel.org/r/20211113121050.7266-1-sven@narfation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250_bcm7271: UART errors after resuming from S2Al Cooper1-0/+13
[ Upstream commit 9cabe26e65a893afd5846908aa393bd283ab6609 ] There is a small window in time during resume where the hardware flow control signal RTS can be asserted (which allows a sender to resume sending data to the UART) but the baud rate has not yet been restored. This will cause corrupted data and FRAMING, OVERRUN and BREAK errors. This is happening because the MCTRL register is shadowed in uart_port struct and is later used during resume to set the MCTRL register during both serial8250_do_startup() and uart_resume_port(). Unfortunately, serial8250_do_startup() happens before the UART baud rate is restored. The fix is to clear the shadowed mctrl value at the end of suspend and restore it at the end of resume. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Al Cooper <alcooperx@gmail.com> Link: https://lore.kernel.org/r/20211201201402.47446-1-alcooperx@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: cpm_uart: Protect udbg definitions by CONFIG_SERIAL_CPM_CONSOLEGeert Uytterhoeven1-0/+2
[ Upstream commit d142585bceb3218ad432ed0fcd5be9d6e3cd9052 ] If CONFIG_CONSOLE_POLL=y, and CONFIG_SERIAL_CPM=m (hence CONFIG_SERIAL_CPM_CONSOLE=n): drivers/tty/serial/cpm_uart/cpm_uart_core.c:1109:12: warning: ‘udbg_cpm_getc’ defined but not used [-Wunused-function] 1109 | static int udbg_cpm_getc(void) | ^~~~~~~~~~~~~ drivers/tty/serial/cpm_uart/cpm_uart_core.c:1095:13: warning: ‘udbg_cpm_putc’ defined but not used [-Wunused-function] 1095 | static void udbg_cpm_putc(char c) | ^~~~~~~~~~~~~ Fix this by making the udbg definitions depend on CONFIG_SERIAL_CPM_CONSOLE, in addition to CONFIG_CONSOLE_POLL. Fixes: a60526097f42eb98 ("tty: serial: cpm_uart: Add udbg support for enabling xmon") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20211027075326.3270785-1-geert@linux-m68k.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: xilinx_uartps: Fix race condition causing stuck TXAnssi Hannula1-1/+2
[ Upstream commit 88b20f84f0fe47409342669caf3e58a3fc64c316 ] xilinx_uartps .start_tx() clears TXEMPTY when enabling TXEMPTY to avoid any previous TXEVENT event asserting the UART interrupt. This clear operation is done immediately after filling the TX FIFO. However, if the bytes inserted by cdns_uart_handle_tx() are consumed by the UART before the TXEMPTY is cleared, the clear operation eats the new TXEMPTY event as well, causing cdns_uart_isr() to never receive the TXEMPTY event. If there are bytes still queued in circbuf, TX will get stuck as they will never get transferred to FIFO (unless new bytes are queued to circbuf in which case .start_tx() is called again). While the racy missed TXEMPTY occurs fairly often with short data sequences (e.g. write 1 byte), in those cases circbuf is usually empty so no action on TXEMPTY would have been needed anyway. On the other hand, longer data sequences make the race much more unlikely as UART takes longer to consume the TX FIFO. Therefore it is rare for this race to cause visible issues in general. Fix the race by clearing the TXEMPTY bit in ISR *before* filling the FIFO. The TXEMPTY bit in ISR will only get asserted at the exact moment the TX FIFO *becomes* empty, so clearing the bit before filling FIFO does not cause an extra immediate assertion even if the FIFO is initially empty. This is hard to reproduce directly on a normal system, but inserting e.g. udelay(200) after cdns_uart_handle_tx(port), setting 4000000 baud, and then running "dd if=/dev/zero bs=128 of=/dev/ttyPS0 count=50" reliably reproduces the issue on my ZynqMP test system unless this fix is applied. Fixes: 85baf542d54e ("tty: xuartps: support 64 byte FIFO size") Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi> Link: https://lore.kernel.org/r/20211026102741.2910441-1-anssi.hannula@bitwise.fi Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: imx: fix detach/attach of serial consoleStefan Agner1-2/+2
[ Upstream commit 6d0d1b5a1b4870911beb89544ec1a9751c42fec7 ] If the device used as a serial console gets detached/attached at runtime, register_console() will try to call imx_uart_setup_console(), but this is not possible since it is marked as __init. For instance # cat /sys/devices/virtual/tty/console/active tty1 ttymxc0 # echo -n N > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console # echo -n Y > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console [ 73.166649] 8<--- cut here --- [ 73.167005] Unable to handle kernel paging request at virtual address c154d928 [ 73.167601] pgd = 55433e84 [ 73.167875] [c154d928] *pgd=8141941e(bad) [ 73.168304] Internal error: Oops: 8000000d [#1] SMP ARM [ 73.168429] Modules linked in: [ 73.168522] CPU: 0 PID: 536 Comm: sh Not tainted 5.15.0-rc6-00056-g3968ddcf05fb #3 [ 73.168675] Hardware name: Freescale i.MX6 Ultralite (Device Tree) [ 73.168791] PC is at imx_uart_console_setup+0x0/0x238 [ 73.168927] LR is at try_enable_new_console+0x98/0x124 [ 73.169056] pc : [<c154d928>] lr : [<c0196f44>] psr: a0000013 [ 73.169178] sp : c2ef5e70 ip : 00000000 fp : 00000000 [ 73.169281] r10: 00000000 r9 : c02cf970 r8 : 00000000 [ 73.169389] r7 : 00000001 r6 : 00000001 r5 : c1760164 r4 : c1e0fb08 [ 73.169512] r3 : c154d928 r2 : 00000000 r1 : efffcbd1 r0 : c1760164 [ 73.169641] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 73.169782] Control: 10c5387d Table: 8345406a DAC: 00000051 [ 73.169895] Register r0 information: non-slab/vmalloc memory [ 73.170032] Register r1 information: non-slab/vmalloc memory [ 73.170158] Register r2 information: NULL pointer [ 73.170273] Register r3 information: non-slab/vmalloc memory [ 73.170397] Register r4 information: non-slab/vmalloc memory [ 73.170521] Register r5 information: non-slab/vmalloc memory [ 73.170647] Register r6 information: non-paged memory [ 73.170771] Register r7 information: non-paged memory [ 73.170892] Register r8 information: NULL pointer [ 73.171009] Register r9 information: non-slab/vmalloc memory [ 73.171142] Register r10 information: NULL pointer [ 73.171259] Register r11 information: NULL pointer [ 73.171375] Register r12 information: NULL pointer [ 73.171494] Process sh (pid: 536, stack limit = 0xcd1ba82f) [ 73.171621] Stack: (0xc2ef5e70 to 0xc2ef6000) [ 73.171731] 5e60: ???????? ???????? ???????? ???????? [ 73.171899] 5e80: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172059] 5ea0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172217] 5ec0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172377] 5ee0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172537] 5f00: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172698] 5f20: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.172856] 5f40: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173016] 5f60: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173177] 5f80: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173336] 5fa0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173496] 5fc0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173654] 5fe0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.173826] [<c0196f44>] (try_enable_new_console) from [<c01984a8>] (register_console+0x10c/0x2ec) [ 73.174053] [<c01984a8>] (register_console) from [<c06e2c90>] (console_store+0x14c/0x168) [ 73.174262] [<c06e2c90>] (console_store) from [<c0383718>] (kernfs_fop_write_iter+0x110/0x1cc) [ 73.174470] [<c0383718>] (kernfs_fop_write_iter) from [<c02cf5f4>] (vfs_write+0x31c/0x548) [ 73.174679] [<c02cf5f4>] (vfs_write) from [<c02cf970>] (ksys_write+0x60/0xec) [ 73.174863] [<c02cf970>] (ksys_write) from [<c0100080>] (ret_fast_syscall+0x0/0x1c) [ 73.175052] Exception stack(0xc2ef5fa8 to 0xc2ef5ff0) [ 73.175167] 5fa0: ???????? ???????? ???????? ???????? ???????? ???????? [ 73.175327] 5fc0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ???????? [ 73.175486] 5fe0: ???????? ???????? ???????? ???????? [ 73.175608] Code: 00000000 00000000 00000000 00000000 (00000000) [ 73.175744] ---[ end trace 9b75121265109bf1 ]--- A similar issue could be triggered by unbinding/binding the serial console device [*]. Drop __init so that imx_uart_setup_console() can be safely called at runtime. [*] https://lore.kernel.org/all/20181114174940.7865-3-stefan@agner.ch/ Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com> Link: https://lore.kernel.org/r/20211020192643.476895-2-francesco.dolcini@toradex.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: 8250_dw: Drop wrong use of ACPI_PTR()Andy Shevchenko1-1/+1
[ Upstream commit ebabb77a2a115b6c5e68f7364b598310b5f61fb2 ] ACPI_PTR() is more harmful than helpful. For example, in this case if CONFIG_ACPI=n, the ID table left unused which is not what we want. Instead of adding ifdeffery here and there, drop ACPI_PTR(). Fixes: 6a7320c4669f ("serial: 8250_dw: Add ACPI 5.0 support") Reported-by: Daniel Palmer <daniel@0x0f.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211005134516.23218-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18Revert "serial: 8250: Fix reporting real baudrate value in c_ospeed field"Johan Hovold1-17/+0
commit d02b006b29de14968ba4afa998bede0d55469e29 upstream. This reverts commit 32262e2e429cdb31f9e957e997d53458762931b7. The commit in question claims to determine the inverse of serial8250_get_divisor() but failed to notice that some drivers override the default implementation using a get_divisor() callback. This means that the computed line-speed values can be completely wrong and results in regular TCSETS requests failing (the incorrect values would also be passed to any overridden set_divisor() callback). Similarly, it also failed to honour the old (deprecated) ASYNC_SPD_FLAGS and would break applications relying on those when re-encoding the actual line speed. There are also at least two quirks, UART_BUG_QUOT and an OMAP1510 workaround, which were happily ignored and that are now broken. Finally, even if the offending commit were to be implemented correctly, this is a new feature and not something which should be backported to stable. Cc: Pali Rohár <pali@kernel.org> Fixes: 32262e2e429c ("serial: 8250: Fix reporting real baudrate value in c_ospeed field") Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211007133146.28949-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18serial: 8250: Fix reporting real baudrate value in c_ospeed fieldPali Rohár1-0/+17
commit 32262e2e429cdb31f9e957e997d53458762931b7 upstream. In most cases it is not possible to set exact baudrate value to hardware. So fix reporting real baudrate value which was set to hardware via c_ospeed termios field. It can be retrieved by ioctl(TCGETS2) from userspace. Real baudrate value is calculated from chosen hardware divisor and base clock. It is implemented in a new function serial8250_compute_baud_rate() which is inverse of serial8250_get_divisor() function. With this change is fixed also UART timeout value (it is updated via uart_update_timeout() function), which is calculated from the now fixed baudrate value too. Cc: stable@vger.kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20210927093704.19768-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18serial: 8250: fix racy uartclk updateJohan Hovold1-4/+17
commit 211cde4f5817dc88ef7f8f2fa286e57fbf14c8ee upstream. Commit 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method") added a hack to support SoCs where the UART reference clock can change behind the back of the driver but failed to add the proper locking. First, make sure to take a reference to the tty struct to avoid dereferencing a NULL pointer if the clock change races with a hangup. Second, the termios semaphore must be held during the update to prevent a racing termios change. Fixes: 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method") Fixes: c8dff3aa8241 ("serial: 8250: Skip uninitialized TTY port baud rate update") Cc: stable@vger.kernel.org # 5.9 Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru> Tested-by: Serge Semin <fancer.lancer@gmail.com> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211015111422.1027-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18serial: core: Fix initializing and restoring termios speedPali Rohár1-2/+14
commit 027b57170bf8bb6999a28e4a5f3d78bf1db0f90c upstream. Since commit edc6afc54968 ("tty: switch to ktermios and new framework") termios speed is no longer stored only in c_cflag member but also in new additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag then termios speed is stored only in these new members. Therefore to correctly restore termios speed it is required to store also ispeed and ospeed members, not only cflag member. In case only cflag member with BOTHER flag is restored then functions tty_termios_baud_rate() and tty_termios_input_baud_rate() returns baudrate stored in c_ospeed / c_ispeed member, which is zero as it was not restored too. If reported baudrate is invalid (e.g. zero) then serial core functions report fallback baudrate value 9600. So it means that in this case original baudrate is lost and kernel changes it to value 9600. Simple reproducer of this issue is to boot kernel with following command line argument: "console=ttyXXX,86400" (where ttyXXX is the device name). For speed 86400 there is no Bnnn constant and therefore kernel has to represent this speed via BOTHER c_cflag. Which means that speed is stored only in c_ospeed and c_ispeed members, not in c_cflag anymore. If bootloader correctly configures serial device to speed 86400 then kernel prints boot log to early console at speed speed 86400 without any issue. But after kernel starts initializing real console device ttyXXX then speed is changed to fallback value 9600 because information about speed was lost. This patch fixes above issue by storing and restoring also ispeed and ospeed members, which are required for BOTHER flag. Fixes: edc6afc54968 ("[PATCH] tty: switch to ktermios and new framework") Cc: stable@vger.kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20211002130900.9518-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-05serial: 8250: allow disabling of Freescale 16550 compile testJohan Hovold1-2/+6
The SERIAL_8250_FSL option is used to enable a workaround for a break-detection erratum for Freescale 16550 UARTs in the 8250 driver and is currently also used to enable support for ACPI enumeration. It is enabled on PPC, ARM and ARM64 whenever 8250 console support is enabled (since the quirk is needed for sysrq handling). Commit b1442c55ce89 ("serial: 8250: extend compile-test coverage") enabled compile testing of the code in question but did not provide a means to disable the option when COMPILE_TEST is enabled. Add a conditional input prompt instead so that SERIAL_8250_FSL is no longer enabled by default when compile testing while continuing to always enable the quirk for platforms that may need it. Fixes: b1442c55ce89 ("serial: 8250: extend compile-test coverage") Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20210924141232.4419-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14serial: mvebu-uart: fix driver's tx_empty callbackPali Rohár1-1/+1
Driver's tx_empty callback should signal when the transmit shift register is empty. So when the last character has been sent. STAT_TX_FIFO_EMP bit signals only that HW transmit FIFO is empty, which happens when the last byte is loaded into transmit shift register. STAT_TX_EMP bit signals when the both HW transmit FIFO and transmit shift register are empty. So replace STAT_TX_FIFO_EMP check by STAT_TX_EMP in mvebu_uart_tx_empty() callback function. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable <stable@vger.kernel.org> Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20210911132017.25505-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14serial: 8250: 8250_omap: Fix RX_LVL register offsetNishanth Menon1-1/+1
Commit b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") introduced fixup including a register read to RX_LVL, however, we should be using word offset than byte offset since our registers are on 4 byte boundary (port.regshift = 2) for 8250_omap. Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") Cc: stable <stable@vger.kernel.org> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Nishanth Menon <nm@ti.com> Link: https://lore.kernel.org/r/20210903050550.29050-1-nm@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>