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.h b/drivers/tty/serial/ifx6x60.h
index d8869f5..4fbddc2 100644
--- a/drivers/tty/serial/ifx6x60.h
+++ b/drivers/tty/serial/ifx6x60.h
@@ -41,6 +41,7 @@
#define IFX_SPI_STATE_IO_IN_PROGRESS 1
#define IFX_SPI_STATE_IO_READY 2
#define IFX_SPI_STATE_TIMER_PENDING 3
+#define IFX_SPI_STATE_IO_AVAILABLE 4
/* flow control bitfields */
#define IFX_SPI_DCD 0