diff options
| author | Jun Chen <jun.d.chen@intel.com> | 2012-11-07 12:04:04 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-15 16:51:38 -0800 |
| commit | e8823f1ca8d5a0c5d69a8862682ee8bde26990ca (patch) | |
| tree | 6c8a34829ffc27f8fce93c3230df4f99ef59c98c | |
| parent | 1b2f8a9550f92686fb76f9dd4d0ec7c0c3f1b027 (diff) | |
serial: ifx6x60: ifx_spi_write don't need to do mrdy_assert when fifo is not empty
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.bi@intel.com>
Signed-off-by: Chen Jun <jun.d.chen@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/ifx6x60.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c index 21eb70bcb6a..1754c147a94 100644 --- a/drivers/tty/serial/ifx6x60.c +++ b/drivers/tty/serial/ifx6x60.c @@ -508,9 +508,16 @@ 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); + 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); + int 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; } |