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@xxxxxxxxx>
Signed-off-by: Chen Jun <jun.d.chen@xxxxxxxxx>
---
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 a688f8f..4a21f5e 100644
--- a/drivers/tty/serial/ifx6x60.c
+++ b/drivers/tty/serial/ifx6x60.c
@@ -520,9 +520,16 @@ 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;
}
--
1.7.4.1
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