dmaengine: dmatest: Don't forcibly terminate channel in polled mode

Commit Message

Nathan Lynch April 8, 2025, 1:37 p.m. UTC

From: Nathan Lynch <[e-mail]>

Invoking dmaengine_terminate_sync() against the channel after each
submitted descriptor is strange. It's benign when the test is
single-threaded, but disruptive when multiple threads are submitting
descriptors to the channel concurrently:

  # cd /sys/module/dmatest/parameters/
  # echo 1 > polled
  # echo 2 > threads_per_chan
  # echo dma0chan0 > channel
  # echo 1 > run
...
  dmatest: Added 2 threads using dma0chan0
  dmatest: Started 2 threads using dma0chan0
  xilinx-zynqmp-dma ffa80000.dma: dma_sync_wait: timeout!
  xilinx-zynqmp-dma ffa80000.dma: dma_sync_wait: timeout!
  dmatest: dma0chan0-copy0: result #3: 'test timed out' with
    src_off=0x487 dst_off=0xf8 len=0x171b (0)
  dmatest: dma0chan0-copy1: result #6: 'test timed out' with
    src_off=0x227d dst_off=0xf99 len=0xf7a (0)

Remove the call to dmaengine_terminate_sync() from the main thread
loop.

Fixes: fb9816f9d05f ("dmaengine: dmatest: Add support for completion polling")
Signed-off-by: Nathan Lynch <[e-mail]>
---
 drivers/dma/dmatest.c | 1 -
 1 file changed, 1 deletion(-)


---
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
change-id: 20250403-dmaengine-dmatest-poll-mode-fix-671b02dc9084

Best regards,

Patch

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index d891dfca358e209c9a5c2d8b49e3e539130e53e8..4e109c45fe0c5a7e8f337efe6e00e0616977f770 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -835,7 +835,6 @@  static int dmatest_func(void *data)
 
 		if (params->polled) {
 			status = dma_sync_wait(chan, cookie);
-			dmaengine_terminate_sync(chan);
 			if (status == DMA_COMPLETE)
 				done->done = true;
 		} else {