[PATCH v2 5/6] dmaengine: ti: k3-udma: Use the channel direction in pause/resume functions

Peter Ujfalusi
2020-02-14T09:14:56Z

It should be possible to pause, resume and check the pause state of a
channel even if we do not have active transfer.

udma_is_chan_paused() can trigger NULL pointer reference in it's current
form when the status is checked while uc->desc is NULL.

Fixes: 25dcb5dd7b7ce ("dmaengine: ti: New driver for K3 UDMA")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
drivers/dma/ti/k3-udma.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index 1dba47c662c4..9b4e1e5fa849 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -513,7 +513,7 @@ static bool udma_is_chan_paused(struct udma_chan *uc)
{
u32 val, pause_mask;

- switch (uc->desc->dir) {
+ switch (uc->config.dir) {
case DMA_DEV_TO_MEM:
val = udma_rchanrt_read(uc->rchan,
UDMA_RCHAN_RT_PEER_RT_EN_REG);
@@ -2835,11 +2835,8 @@ static int udma_pause(struct dma_chan *chan)
{
struct udma_chan *uc = to_udma_chan(chan);

- if (!uc->desc)
- return -EINVAL;
-
/* pause the channel */
- switch (uc->desc->dir) {
+ switch (uc->config.dir) {
case DMA_DEV_TO_MEM:
udma_rchanrt_update_bits(uc->rchan,
UDMA_RCHAN_RT_PEER_RT_EN_REG,
@@ -2868,11 +2865,8 @@ static int udma_resume(struct dma_chan *chan)
{
struct udma_chan *uc = to_udma_chan(chan);

- if (!uc->desc)
- return -EINVAL;
-
/* resume the channel */
- switch (uc->desc->dir) {
+ switch (uc->config.dir) {
case DMA_DEV_TO_MEM:
udma_rchanrt_update_bits(uc->rchan,
UDMA_RCHAN_RT_PEER_RT_EN_REG,