From: Vinod Koul <vkoul@kernel.org>
To: Eric Pilmore <epilmore@gigaio.com>
Cc: "Mehta, Sanju" <Sanju.Mehta@amd.com>, dmaengine@vger.kernel.org
Subject: Re: [RESEND PATCH] dmaengine: ptdma: check for null desc before calling pt_cmd_callback
Date: Fri, 10 Feb 2023 11:25:58 +0530 [thread overview]
Message-ID: <Y+Xcbip4dO4qSP4H@matsya> (raw)
In-Reply-To: <CAOQPn8tpjo5Jwz8jGi0JfTQd-hF+VS7N90T=GJpjG3wj5x8UHw@mail.gmail.com>
On 09-02-23, 21:37, Eric Pilmore wrote:
> From: Eric Pilmore <epilmore@gigaio.com>
>
> 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")
This should not be split two two lines!
> Signed-off-by: Eric Pilmore <epilmore@gigaio.com>
> ---
> drivers/dma/ptdma/ptdma-dmaengine.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> 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)
Please run checkpatch before sending patches
WARNING: please, no spaces at the start of a line
#40: FILE: drivers/dma/ptdma/ptdma-dmaengine.c:257:
+ if (engine_is_idle && desc)$
WARNING: suspect code indent for conditional statements (7, 15)
#40: FILE: drivers/dma/ptdma/ptdma-dmaengine.c:257:
+ if (engine_is_idle && desc)
pt_cmd_callback(desc, 0);
> pt_cmd_callback(desc, 0);
> }
>
> --
> 2.38.1
--
~Vinod
prev parent reply other threads:[~2023-02-10 5:56 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-10 5:37 [RESEND PATCH] dmaengine: ptdma: check for null desc before calling pt_cmd_callback Eric Pilmore
2023-02-10 5:55 ` Vinod Koul [this message]
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