From: Geert Uytterhoeven Date: Fri, 21 Aug 2015 18:02:57 +0000 (+0200) Subject: serial: sh-sci: Don't call sci_dma_rx_push() if no data has arrived X-Git-Tag: firefly_0821_release~176^2~803^2~107 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=99dc8e400e93773fb45c57cc969c7be443d98141;p=firefly-linux-kernel-4.4.55.git serial: sh-sci: Don't call sci_dma_rx_push() if no data has arrived On receive DMA time-out, avoid calling sci_dma_rx_push() if no data was transferred by the timed out DMA request. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index ffcbf6eaf5f9..d8b73e791a55 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1467,10 +1467,11 @@ static void work_fn_rx(struct work_struct *work) dev_dbg(port->dev, "Read %u bytes with cookie %d\n", read, s->active_rx); - count = sci_dma_rx_push(s, s->rx_buf[new], read); - - if (count) - tty_flip_buffer_push(&port->state->port); + if (read) { + count = sci_dma_rx_push(s, s->rx_buf[new], read); + if (count) + tty_flip_buffer_push(&port->state->port); + } spin_unlock_irqrestore(&port->lock, flags);