diff options
| author |   chao bi <chao.bi@intel.com> | 2012-10-31 16:54:07 +0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-01 08:50:01 -0700 |
| commit | 31fe99048859b13a87f476016e7bb5c2b5220c36 (patch) | |
| tree | 425b1ce34168d16470530f21b87f92b1ec077093 /drivers/tty/serial/ifx6x60.c | |
| parent | serial/arc-uart: Add new driver (diff) | |
| download | linux-dev-31fe99048859b13a87f476016e7bb5c2b5220c36.tar.xz linux-dev-31fe99048859b13a87f476016e7bb5c2b5220c36.zip | |
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.c | 11 |
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--; |