dmaengine: ti: k3-udma: Set bchan to NULL if a channel request fail

bcdma_get_*() checks if bchan is already allocated by checking if it
has a NON NULL value. For the error cases, bchan will have error value
and bcdma_get_*() considers this as already allocated (PASS) since the
error values are NON NULL. This results in NULL pointer dereference
error while de-referencing bchan.

Reset the value of bchan to NULL if a channel request fails.

CC: stable@vger.kernel.org
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20211031032411.27235-2-kishon@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Kishon Vijay Abraham I 2021-10-31 08:54:10 +05:30 committed by Vinod Koul
parent 2498363310
commit 5c6c6d60e4

View file

@ -1348,6 +1348,7 @@ static int bcdma_get_bchan(struct udma_chan *uc)
{
struct udma_dev *ud = uc->ud;
enum udma_tp_level tpl;
int ret;
if (uc->bchan) {
dev_dbg(ud->dev, "chan%d: already have bchan%d allocated\n",
@ -1365,8 +1366,11 @@ static int bcdma_get_bchan(struct udma_chan *uc)
tpl = ud->bchan_tpl.levels - 1;
uc->bchan = __udma_reserve_bchan(ud, tpl, -1);
if (IS_ERR(uc->bchan))
return PTR_ERR(uc->bchan);
if (IS_ERR(uc->bchan)) {
ret = PTR_ERR(uc->bchan);
uc->bchan = NULL;
return ret;
}
uc->tchan = uc->bchan;