From 947c74eba85bff743bc15adbdd9193ffff60c29f Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Fri, 11 Oct 2013 18:31:00 +0800 Subject: [PATCH] serial: imx: fix the wrong number of scatterlist entries when xmit->head is 0 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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, -- 2.7.4