| Message ID | 20230210075142.58253-1-epilmore@gigaio.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 0a60cc31858f289b8592c029a3bc109ff956f086 |
| Headers | show |
| Series | [v2] dmaengine: ptdma: check for null desc before calling pt_cmd_callback | expand |
On 09-02-23, 23:51, Eric Pilmore wrote: > Resolves a panic that can occur on AMD systems, typically during host > shutdown, after the PTDMA driver had been exercised. The issue was > the pt_issue_pending() function is mistakenly assuming that there will > be at least one descriptor in the Submitted queue when the function > is called. However, it is possible that both the Submitted and Issued > queues could be empty, which could result in pt_cmd_callback() being > mistakenly called with a NULL pointer. > Ref: Bugzilla Bug 216856. Applied, thanks
diff --git a/drivers/dma/ptdma/ptdma-dmaengine.c b/drivers/dma/ptdma/ptdma-dmaengine.c index cc22d162ce25..1aa65e5de0f3 100644 --- a/drivers/dma/ptdma/ptdma-dmaengine.c +++ b/drivers/dma/ptdma/ptdma-dmaengine.c @@ -254,7 +254,7 @@ static void pt_issue_pending(struct dma_chan *dma_chan) spin_unlock_irqrestore(&chan->vc.lock, flags); /* If there was nothing active, start processing */ - if (engine_is_idle) + if (engine_is_idle && desc) pt_cmd_callback(desc, 0); }
Resolves a panic that can occur on AMD systems, typically during host shutdown, after the PTDMA driver had been exercised. The issue was the pt_issue_pending() function is mistakenly assuming that there will be at least one descriptor in the Submitted queue when the function is called. However, it is possible that both the Submitted and Issued queues could be empty, which could result in pt_cmd_callback() being mistakenly called with a NULL pointer. Ref: Bugzilla Bug 216856. Fixes: 6fa7e0e836e2 ("dmaengine: ptdma: fix concurrency issue with multiple dma transfer") Signed-off-by: Eric Pilmore <epilmore@gigaio.com> --- v2: clean-up patch format drivers/dma/ptdma/ptdma-dmaengine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)