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Date: Fri, 7 Jun 2024 13:00:20 +0200
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Subject: Re: [PATCH v2] dmaengine: xilinx: xdma: Fix data synchronisation in
 xdma_channel_isr()
To: Louis Chauvet <louis.chauvet@bootlin.com>, Lizhi Hou <lizhi.hou@amd.com>,
 Brian Xu <brian.xu@amd.com>, Raj Kumar Rampelli
 <raj.kumar.rampelli@amd.com>, Vinod Koul <vkoul@kernel.org>,
 Michal Simek <michal.simek@amd.com>, dmaengine@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org
References: <20240607-xdma-fixes-v2-1-0282319ce345@bootlin.com>
Content-Language: en-GB
From: Markus Elfring <Markus.Elfring@web.de>
In-Reply-To: <20240607-xdma-fixes-v2-1-0282319ce345@bootlin.com>
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> Requests the vchan lock before using xdma->stop_request.

Better wording alternative?:
  A data synchronisation construct was missing in this function implementa=
tion.
  Thus apply the vchan lock before checking the data structure
  member =E2=80=9Cxchan->stop_requested=E2=80=9D.


> ---
>  drivers/dma/xilinx/xdma.c | 4 ++--

How do think about to avoid a duplicate marker line?


=E2=80=A6
> +++ b/drivers/dma/xilinx/xdma.c
> @@ -885,11 +885,11 @@ static irqreturn_t xdma_channel_isr(int irq, void =
*dev_id)
>  	u32 st;
>  	bool repeat_tx;
>
> +	spin_lock(&xchan->vchan.lock);
> +
>  	if (xchan->stop_requested)
>  		complete(&xchan->last_interrupt);
>
> -	spin_lock(&xchan->vchan.lock);
> -
>  	/* get submitted request */
=E2=80=A6

Under which circumstances will development interests grow for the usage of
a statement like =E2=80=9Cguard(raw_spinlock)(&xchan->vchan.lock);=E2=80=
=9D?
https://elixir.bootlin.com/linux/v6.10-rc2/source/include/linux/cleanup.h#=
L124

Regards,
Markus