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>
diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c
index e595c83..fbda374 100644
--- a/drivers/tty/serial/ifx6x60.c
+++ b/drivers/tty/serial/ifx6x60.c
@@ -569,12 +569,19 @@
/* 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 @@
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 @@
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--;