serial: imx: always wake up the processes in the TX callback
authorHuang Shijie <b32955@freescale.com>
Wed, 22 Jan 2014 08:23:37 +0000 (16:23 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 13 Feb 2014 18:18:48 +0000 (10:18 -0800)
The current code only wakes up the processes when the circle
buffer has less data then the WAKEUP_CHARS.

But sometimes, the circle buffer may has data more then the WAKEUP_CHARS,
in such case, the processes will hang.

This patch makes it always wakes up the processes in the TX callback.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/imx.c

index d799140e53b6a649b51ace8129b8846ed695a824..dff0f0a472ea3591fa5209f1329c04c7f233e217 100644 (file)
@@ -496,8 +496,7 @@ static void dma_tx_callback(void *data)
 
        dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
 
-       if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
-               uart_write_wakeup(&sport->port);
+       uart_write_wakeup(&sport->port);
 
        if (waitqueue_active(&sport->dma_wait)) {
                wake_up(&sport->dma_wait);