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From: Stephen Warren <swarren@wwwdotorg.org>
To: Dmitry Osipenko <digetx@gmail.com>, ldewangan@nvidia.com
Cc: vinod.koul@intel.com, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2] dma: tegra: avoid channel lock up after free
Date: Tue, 30 Oct 2012 12:05:27 -0600	[thread overview]
Message-ID: <509016E7.800@wwwdotorg.org> (raw)
In-Reply-To: <1351552833-4132-1-git-send-email-digetx@gmail.com>

On 10/29/2012 05:20 PM, Dmitry Osipenko wrote:
> Fixed channel "lock up" after free.
> 
> Lock scenario: Channel 1 was allocated and prepared as slave_sg, used and freed.
> Now preparation of cyclic dma on channel 1 will fail with err "DMA configuration
> conflict" because tdc->isr_handler still selected to handle_once_dma_done.
> 
> This happens because tegra_dma_abort_all() won't be called on channel freeing
> if pending list is empty or channel not busy. We need to clear isr_handler
> on channel freeing to avoid locking. Also I added small optimization to prepare
> functions, so current channel type checked before making allocations.

Reviewed-by: Stephen Warren <swarren@nvidia.com>

I believe this looks OK. However, I would like Laxman to also ack/review
this since he wrote the driver.

  parent reply	other threads:[~2012-10-30 18:05 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-28 14:17 [PATCH 2/2] dma: tegra20-apbdma: channel freeing correction Dmitry Osipenko
2012-10-28 14:17 ` Dmitry Osipenko
2012-10-29 15:27 ` Stephen Warren
2012-10-29 23:20   ` [PATCH V2] dma: tegra: avoid channel lock up after free Dmitry Osipenko
2012-10-29 23:28     ` Dmitry Osipenko
2012-10-30 18:05     ` Stephen Warren [this message]
2012-10-31 14:58     ` Laxman Dewangan
     [not found] ` <1351433873-14082-1-git-send-email-digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2012-10-31 14:48   ` [PATCH 2/2] dma: tegra20-apbdma: channel freeing correction Laxman Dewangan
2012-10-31 14:48     ` Laxman Dewangan
2012-10-31 14:48   ` Laxman Dewangan
2012-10-31 14:48     ` Laxman Dewangan

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