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 <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Huang Shijie 2013-10-11 18:31:00 +08:00 committed by Greg Kroah-Hartman
parent 1ce43e58d4
commit 947c74eba8

View File

@ -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,