Re: [PATCH] dmaengine: pl330: Acquire dmac's spinlock in pl330_tx_status

From	Vinod Koul <vinod.koul@intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] dmaengine: pl330: Acquire dmac's spinlock in pl330_tx_status
Date	2016-09-09 13:50 +0200
Message-ID	<sfstH-2h0-11@gated-at.bofh.it> (permalink)
References	<s9g2e-1UK-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Tue, Aug 23, 2016 at 05:16:55PM +0800, Hsin-Yu Chao wrote:
> There is a racing when accessing dmac thread in pl330_tx_status that
> the pl330_update is handling active request at the same time and
> changing the status of descriptors. This could cause an invalid
> transferred count from BUSY descriptor added up to the residual number.
> Fix the bug by using the dmac's spinlock in pl330_tx_status to protect
> thread resources from changing.
> Note that the nested order of holding dmac's and dma_chan's spinlock is
> consistent with the rest of the driver: dma_chan first and then dmac,
> so it is safe from deadlock scenario.

Applied, thanks

-- 
~Vinod

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Re: [PATCH] dmaengine: pl330: Acquire dmac's spinlock in  pl330_tx_status Vinod Koul <vinod.koul@intel.com> - 2016-09-09 13:50 +0200

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