From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sekhar Nori <nsekhar@ti.com>
Subject: Re: [PATCH 1/1] dma: edma: fix incorrect SG list handling
Date: Mon, 14 Apr 2014 14:01:11 +0530
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To: Dan Williams <dan.j.williams@intel.com>, Vinod Koul <vinod.koul@intel.com>
Cc: DMA Engine Mailing List <dmaengine@vger.kernel.org>, Linux DaVinci Mailing List <davinci-linux-open-source@linux.davincidsp.com>, Jon Ringle <jringle@gridpoint.com>, Alexander Holler <holler@ahsoftware.de>, Linux OMAP Mailing List <linux-omap@vger.kernel.org>, Joel Fernandes <joelf@ti.com>

Vinod,

On Wednesday 19 March 2014 11:25 AM, Sekhar Nori wrote:
> The code to handle any length SG lists calls edma_resume()
> even before edma_start() is called. This is incorrect
> because edma_resume() enables edma events on the channel
> after which CPU (in edma_start) cannot clear posted
> events by writing to ECR (per the EDMA user's guide).
> 
> Because of this EDMA transfers fail to start if due
> to some reason there is a pending EDMA event registered
> even before EDMA transfers are started. This can happen if
> an EDMA event is a byproduct of device initialization.
> 
> Fix this by calling edma_resume() only if it is not the
> first batch of MAX_NR_SG elements.
> 
> Without this patch, MMC/SD fails to function on DA850 EVM
> with DMA. The behaviour is triggered by specific IP and
> this can explain why the issue was not reported before
> (example with MMC/SD on AM335x).
> 
> Tested on DA850 EVM and AM335x EVM-SK using MMC/SD card.
> 
> Cc: stable@vger.kernel.org # v3.12.x+
> Cc: Joel Fernandes <joelf@ti.com>
> Acked-by: Joel Fernandes <joelf@ti.com>
> Tested-by: Jon Ringle <jringle@gridpoint.com>
> Tested-by: Alexander Holler <holler@ahsoftware.de>
> Reported-by: Jon Ringle <jringle@gridpoint.com>
> Signed-off-by: Sekhar Nori <nsekhar@ti.com>

Looks like this patch is not in mainline still?

Thanks,
Sekhar