This patch check whether the fifo lenth is empty before writing new data to 
fifo.If condition
is true,ifx_spi_write need to trigger one mrdy_assert. If condition is 
false,the mrdy_assert
will be trigger by the next ifx_spi_io.
Cc: Bi Chao <chao...@intel.com>
Signed-off-by: Chen Jun <jun.d.c...@intel.com>
---
 drivers/tty/serial/ifx6x60.c |   14 +++++++++++---
 1 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c
index 5b9bc19..aa01989 100644
--- a/drivers/tty/serial/ifx6x60.c
+++ b/drivers/tty/serial/ifx6x60.c
@@ -469,9 +469,17 @@ static int ifx_spi_write(struct tty_struct *tty, const 
unsigned char *buf,
 {
        struct ifx_spi_device *ifx_dev = tty->driver_data;
        unsigned char *tmp_buf = (unsigned char *)buf;
-       int tx_count = kfifo_in_locked(&ifx_dev->tx_fifo, tmp_buf, count,
-                                  &ifx_dev->fifo_lock);
-       mrdy_assert(ifx_dev);
+       int tx_count;
+       unsigned long flags;
+       bool is_fifo_empty;
+
+       spin_lock_irqsave(&ifx_dev->fifo_lock, flags);
+       is_fifo_empty = kfifo_is_empty(&ifx_dev->tx_fifo);
+       tx_count = kfifo_in(&ifx_dev->tx_fifo, tmp_buf, count);
+       spin_unlock_irqrestore(&ifx_dev->fifo_lock, flags);
+       if (is_fifo_empty)
+               mrdy_assert(ifx_dev);
+
        return tx_count;
 }
 
-- 
1.7.4.1



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to