diff options
author | Pali Rohár <pali@kernel.org> | 2022-06-28 13:09:22 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-29 18:14:09 +0300 |
commit | c68f6e2e4fda5f36d403f64fa57a2804ec59a87d (patch) | |
tree | 6c6a43eede2de3f4824bf581cf3e3cae55dec62f /drivers | |
parent | 2230428fb866cb2a7a62e35b7aedfd43d3afa797 (diff) | |
download | linux-c68f6e2e4fda5f36d403f64fa57a2804ec59a87d.tar.xz |
serial: mvebu-uart: correctly report configured baudrate value
commit 4f532c1e25319e42996ec18a1f473fd50c8e575d upstream.
Functions tty_termios_encode_baud_rate() and uart_update_timeout() should
be called with the baudrate value which was set to hardware. Linux then
report exact values via ioctl(TCGETS2) to userspace.
Change mvebu_uart_baud_rate_set() function to return baudrate value which
was set to hardware and propagate this value to above mentioned functions.
With this change userspace would see precise value in termios c_ospeed
field.
Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate")
Cc: stable <stable@kernel.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20220628100922.10717-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/tty/serial/mvebu-uart.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c index 13db15118cb9..2ce0d05be368 100644 --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -443,13 +443,13 @@ static void mvebu_uart_shutdown(struct uart_port *port) } } -static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) +static unsigned int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) { unsigned int d_divisor, m_divisor; u32 brdv, osamp; if (!port->uartclk) - return -EOPNOTSUPP; + return 0; /* * The baudrate is derived from the UART clock thanks to two divisors: @@ -473,7 +473,7 @@ static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) osamp &= ~OSAMP_DIVISORS_MASK; writel(osamp, port->membase + UART_OSAMP); - return 0; + return DIV_ROUND_CLOSEST(port->uartclk, d_divisor * m_divisor); } static void mvebu_uart_set_termios(struct uart_port *port, @@ -510,15 +510,11 @@ static void mvebu_uart_set_termios(struct uart_port *port, max_baud = 230400; baud = uart_get_baud_rate(port, termios, old, min_baud, max_baud); - if (mvebu_uart_baud_rate_set(port, baud)) { - /* No clock available, baudrate cannot be changed */ - if (old) - baud = uart_get_baud_rate(port, old, NULL, - min_baud, max_baud); - } else { - tty_termios_encode_baud_rate(termios, baud, baud); - uart_update_timeout(port, termios->c_cflag, baud); - } + baud = mvebu_uart_baud_rate_set(port, baud); + + /* In case baudrate cannot be changed, report previous old value */ + if (baud == 0 && old) + baud = tty_termios_baud_rate(old); /* Only the following flag changes are supported */ if (old) { @@ -529,6 +525,11 @@ static void mvebu_uart_set_termios(struct uart_port *port, termios->c_cflag |= CS8; } + if (baud != 0) { + tty_termios_encode_baud_rate(termios, baud, baud); + uart_update_timeout(port, termios->c_cflag, baud); + } + spin_unlock_irqrestore(&port->lock, flags); } |