[PATCH] dmaengine: xilinx_dma: Use readl_poll_timeout() instead of atomic variant

[Tomi Valkeinen]

All callers of xilinx_dma_poll_timeout() pass a zero delay and a 1
second timeout (XILINX_DMA_LOOP_COUNT). With a zero delay,
readl_poll_timeout_atomic() does not measure wall clock time, and the
actual timeout can be much more than 1 second.

This is very visible when a channel reset never completes, e.g. with a
VDMA whose stream-side clock isn't running. Probe appears to hang, and
only minutes later fails with:

  xilinx-vdma a0050000.dma: reset timeout, cr 4, sr 0
  xilinx-vdma a0050000.dma: Reset channel failed

Switch to readl_poll_timeout(), which checks the deadline against
ktime_get().

Calling xilinx_dma_poll_timeout() from atomic context is still safe even
after this change, as readl_poll_timeout() with zero delay never sleeps.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
---
 drivers/dma/xilinx/xilinx_dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 404235c17353..6e8c786147f7 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -530,7 +530,7 @@ struct xilinx_dma_device {
 #define to_dma_tx_descriptor(tx) \
 	container_of(tx, struct xilinx_dma_tx_descriptor, async_tx)
 #define xilinx_dma_poll_timeout(chan, reg, val, cond, delay_us, timeout_us) \
-	readl_poll_timeout_atomic(chan->xdev->regs + chan->ctrl_offset + reg, \
+	readl_poll_timeout(chan->xdev->regs + chan->ctrl_offset + reg, \
 				  val, cond, delay_us, timeout_us)
 
 /* IO accessors */

---
base-commit: f5098b6bae761e346ebcd9da7f95622c04733cff
change-id: 20260803-xilinx-dma-poll-fix-15ab556a7f58

Best regards,
--  
Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>