When the (xmit->tail > xmit->head) is true and the xmit->head is 0, we only need one DMA scatterlist in actually. Current code uses two DMA scatterlists in this case, this is obviously wrong. This patch fixes it. Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx> --- drivers/tty/serial/imx.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index c6c3b16..cadf7e5 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -532,7 +532,7 @@ static void dma_tx_work(struct work_struct *w) return; } - if (xmit->tail > xmit->head) { + if (xmit->tail > xmit->head && xmit->head > 0) { sport->dma_tx_nents = 2; sg_init_table(sgl, 2); sg_set_buf(sgl, xmit->buf + xmit->tail, -- 1.7.2.rc3 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html