Currently, a local dma_cap_mask_t variable is used to store device
cap_mask within udma_of_xlate(). However, the DMA_PRIVATE flag in
the device cap_mask can get cleared when the last channel is released.
This can happen right after storing the cap_mask locally in
udma_of_xlate(), and subsequent dma_request_channel() can fail due to
mismatch in the cap_mask. Fix this by removing the local dma_cap_mask_t
variable and directly using the one from the dma_device structure.

Fixes: 25dcb5dd7b7c ("dmaengine: ti: New driver for K3 UDMA")
Cc: stable@vger.kernel.org
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Reviewed-by: Udit Kumar <u-kumar1@ti.com>
Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
---
 drivers/dma/ti/k3-udma.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index b223a7aacb0c..08ed8cd7f1dd 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -4246,7 +4246,6 @@ static struct dma_chan *udma_of_xlate(struct of_phandle_args *dma_spec,
 				      struct of_dma *ofdma)
 {
 	struct udma_dev *ud = ofdma->of_dma_data;
-	dma_cap_mask_t mask = ud->ddev.cap_mask;
 	struct udma_filter_param filter_param;
 	struct dma_chan *chan;
 
@@ -4278,7 +4277,7 @@ static struct dma_chan *udma_of_xlate(struct of_phandle_args *dma_spec,
 		}
 	}
 
-	chan = __dma_request_channel(&mask, udma_dma_filter_fn, &filter_param,
+	chan = __dma_request_channel(&ud->ddev.cap_mask, udma_dma_filter_fn, &filter_param,
 				     ofdma->of_node);
 	if (!chan) {
 		dev_err(ud->dev, "get channel fail in %s.\n", __func__);
-- 
2.34.1

On Thu, 17 Apr 2025 13:25:21 +0530, Yemike Abhilash Chandra wrote:
> Currently, a local dma_cap_mask_t variable is used to store device
> cap_mask within udma_of_xlate(). However, the DMA_PRIVATE flag in
> the device cap_mask can get cleared when the last channel is released.
> This can happen right after storing the cap_mask locally in
> udma_of_xlate(), and subsequent dma_request_channel() can fail due to
> mismatch in the cap_mask. Fix this by removing the local dma_cap_mask_t
> variable and directly using the one from the dma_device structure.
> 
> [...]

Applied, thanks!

[1/1] dmaengine: ti: k3-udma: Use cap_mask directly from dma_device structure instead of a local copy
      commit: 8ca9590c39b69b55a8de63d2b21b0d44f523b43a

Best regards,
-- 
~Vinod