dmaengine: ti: k3-udma: Use the channel direction in pause/resume functions

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>
Link: https://lore.kernel.org/r/20200214091441.27535-6-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index 1dba47c..9b4e1e5 100644 (file)
--- 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,