serial: ifx6x60: ifx_spi_write don't need to do mrdy_assert when fifo is not empty
PATCH 1/1 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 <[email protected]>
Signed-off-by Chen Jun <[email protected]>
--- drivers/tty/serial/ifx6x60.c | 14 +++++++++++--- 1 files changed, 11 insertions(+), 3 deletions(-)
drivers/tty/serial/ifx6x60.c +11 -3
@@ -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; }
Signature · 1 line
1.7.4.1