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authorchao bi <chao.bi@intel.com>2012-10-31 12:54:07 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-01 19:50:01 +0400
commit31fe99048859b13a87f476016e7bb5c2b5220c36 (patch)
tree425b1ce34168d16470530f21b87f92b1ec077093 /drivers/tty/serial/ifx6x60.c
parent2ac4ad2a1468123f6bb439a547880a9c0d302e0a (diff)
downloadlinux-31fe99048859b13a87f476016e7bb5c2b5220c36.tar.xz
serial:ifx6x60:Prevent data transfer when IFX6x60 port is shutdown
This patch is to implement following 2 places to avoid potential error when IFX6x60 port shutdown: 1) Clear Flag IFX_SPI_STATE_IO_AVAILABLE to disable data transfer when Modem port is shutdown; 2) Clear Flag IFX_SPI_STATE_IO_IN_PROGRESS and IFX_SPI_STATE_IO_READY when reopen port. This is because last port shutdown may happen when SPI/DMA transfer is in progress, if the last data transfer is not completed(for example due to modem reset), the Flag IFX_SPI_STATE_IO_IN_PROGRESS will be set forever, so when IFX port is activated again, IFX_SPI_STATE_IO_IN_PROGRESS will prevent transferring data forever. And if don't clear IFX_SPI_STATE_IO_READY, it may cause one more SPI frame transferring in spit there is not data need to be transfer. cc: liu chuansheng <chuansheng.liu@intel.com> cc: Chen Jun <jun.d.chen@intel.com> Signed-off-by: channing <chao.bi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/ifx6x60.c')
-rw-r--r--drivers/tty/serial/ifx6x60.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c
index e595c832be20..fbda37415f01 100644
--- a/drivers/tty/serial/ifx6x60.c
+++ b/drivers/tty/serial/ifx6x60.c
@@ -569,12 +569,19 @@ static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty)
/* clear any old data; can't do this in 'close' */
kfifo_reset(&ifx_dev->tx_fifo);
+ /* clear any flag which may be set in port shutdown procedure */
+ clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
+ clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
+
/* put port data into this tty */
tty->driver_data = ifx_dev;
/* allows flip string push from int context */
tty->low_latency = 1;
+ /* set flag to allows data transfer */
+ set_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
+
return 0;
}
@@ -590,6 +597,7 @@ static void ifx_port_shutdown(struct tty_port *port)
struct ifx_spi_device *ifx_dev =
container_of(port, struct ifx_spi_device, tty_port);
+ clear_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
mrdy_set_low(ifx_dev);
clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
tasklet_kill(&ifx_dev->io_work_tasklet);
@@ -745,7 +753,8 @@ static void ifx_spi_io(unsigned long data)
int retval;
struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *) data;
- if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags)) {
+ if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags) &&
+ test_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags)) {
if (ifx_dev->gpio.unack_srdy_int_nb > 0)
ifx_dev->gpio.unack_srdy_int_nb--;