when audio playback is running, user space will call
snd_pcm_lib_write1() function, it will first get pcm stream lock,
after that it may call function snd_pcm_update_hw_ptr(), the call
stack will be as below:
snd_pcm_lib_write1 <-- got pcm stream lock
--> snd_pcm_update_hw_ptr
--> dwc_tx_status
--> dwc_scan_descriptors
--> callback
--> dmaengine_pcm_dma_complete
--> snd_pcm_period_elapsed <-- get stream lock again
recursion lock occurs in snd_pcm_period_elapsed function.
remove dwc_scan_descriptors from dwc_tx_status can fix this issue.
Signed-off-by: Yitian Bu <[email protected]>
---
drivers/dma/dw/core.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index cf1c87f..5341b44 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -1078,11 +1078,7 @@ dwc_tx_status(struct dma_chan *chan,
ret = dma_cookie_status(chan, cookie, txstate);
if (ret == DMA_COMPLETE)
return ret;
-
- dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
-
- ret = dma_cookie_status(chan, cookie, txstate);
- if (ret != DMA_COMPLETE)
+ else
dma_set_residue(txstate, dwc_get_residue(dwc));
if (dwc->paused && ret == DMA_IN_PROGRESS)
--
1.7.12.4
Yitian
Best Regards
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