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From: zhangfei <zhangfei.gao@linaro.org>
To: John Stultz <john.stultz@linaro.org>,
	lkml <linux-kernel@vger.kernel.org>
Cc: Jingoo Han <jg1.han@samsung.com>,
	Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	Maxime Ripard <maxime.ripard@free-electrons.com>,
	Vinod Koul <vinod.koul@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Mark Brown <broonie@kernel.org>, Andy Green <andy@warmcat.com>
Subject: Re: [PATCH 6/7] k3dma: Fix occasional DMA ERR issue by using proper dma api
Date: Thu, 21 Jul 2016 12:26:48 +0800	[thread overview]
Message-ID: <57904F08.7020109@linaro.org> (raw)
In-Reply-To: <1469073189-9167-7-git-send-email-john.stultz@linaro.org>



On 07/21/2016 11:53 AM, John Stultz wrote:
> After lots of debugging on an occasional DMA ERR issue, I realized
> that the desc structures which we point the dma hardware are being
> allocated out of regular memory. This means when we fill the desc
> structures, that data doesn't always get flushed out to memory by
> the time we start the dma transfer, resulting in the dma engine getting
> some null values, resulting in a DMA ERR on the first irq.

How about using wmb() flush before start dma to sync desc?

I remember I used dma_pool first, then do some optimization referring 
Russell's driver.

Thanks

  reply	other threads:[~2016-07-21  4:26 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-21  3:53 [PATCH 0/7 v3] K3DMA fixes for HiKey HDMI audio John Stultz
2016-07-21  3:53 ` [PATCH 1/7] k3dma: Fix hisi burst clipping John Stultz
2016-07-24  7:25   ` Vinod Koul
2016-07-29 22:40     ` John Stultz
2016-08-04 13:08       ` Vinod Koul
2016-08-04 17:36         ` John Stultz
2016-08-05  3:36           ` Vinod Koul
2016-07-21  3:53 ` [PATCH 2/7] k3dma: Fix dma err offsets John Stultz
2016-07-21  3:53 ` [PATCH 3/7] k3dma: Fix "nobody cared" message seen on any error John Stultz
2016-07-21  3:53 ` [PATCH 4/7] k3dma: Add cyclic mode for audio John Stultz
2016-07-24  7:31   ` Vinod Koul
2016-07-29 22:38     ` John Stultz
2016-07-21  3:53 ` [PATCH 5/7] k3dma: Fix memory handling with cyclic mode John Stultz
2016-07-21  3:53 ` [PATCH 6/7] k3dma: Fix occasional DMA ERR issue by using proper dma api John Stultz
2016-07-21  4:26   ` zhangfei [this message]
2016-07-21  5:22     ` John Stultz
2016-07-21  6:27       ` Andy Green
2016-07-21 10:40         ` Mark Brown
2016-07-21 13:12           ` Andy Green
2016-07-21 16:18         ` John Stultz
2016-07-21 19:57           ` Andy Green
2016-07-21 16:08       ` zhangfei
2016-07-21  3:53 ` [PATCH 7/7] Kconfig: Allow k3dma driver to be selected for more then HISI3xx platforms John Stultz
2016-07-22  6:56   ` kbuild test robot

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