Re: [PATCH 1/1] dma: edma: fix incorrect SG list handling
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: sta...@vger.kernel.org # v3.12.x+ Cc: Joel Fernandes jo...@ti.com Acked-by: Joel Fernandes jo...@ti.com Tested-by: Jon Ringle jrin...@gridpoint.com Tested-by: Alexander Holler hol...@ahsoftware.de Reported-by: Jon Ringle jrin...@gridpoint.com Signed-off-by: Sekhar Nori nsek...@ti.com Looks like this patch is not in mainline still? Thanks, Sekhar ___ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
Re: [PATCH 1/1] dma: edma: fix incorrect SG list handling
On Mon, Apr 14, 2014 at 02:01:11PM +0530, Sekhar Nori wrote: 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: sta...@vger.kernel.org # v3.12.x+ Cc: Joel Fernandes jo...@ti.com Acked-by: Joel Fernandes jo...@ti.com Tested-by: Jon Ringle jrin...@gridpoint.com Tested-by: Alexander Holler hol...@ahsoftware.de Reported-by: Jon Ringle jrin...@gridpoint.com Signed-off-by: Sekhar Nori nsek...@ti.com Looks like this patch is not in mainline still? Sorry looks like I have missed sending the email. I had applied it last week and today rebased after rc1. It would be part of rc2... -- ~Vinod Thanks, Sekhar -- ___ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
Re: [PATCH 1/1] dma: edma: fix incorrect SG list handling
On Monday 14 April 2014 02:27 PM, Vinod Koul wrote: On Mon, Apr 14, 2014 at 02:01:11PM +0530, Sekhar Nori wrote: 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: sta...@vger.kernel.org # v3.12.x+ Cc: Joel Fernandes jo...@ti.com Acked-by: Joel Fernandes jo...@ti.com Tested-by: Jon Ringle jrin...@gridpoint.com Tested-by: Alexander Holler hol...@ahsoftware.de Reported-by: Jon Ringle jrin...@gridpoint.com Signed-off-by: Sekhar Nori nsek...@ti.com Looks like this patch is not in mainline still? Sorry looks like I have missed sending the email. I had applied it last week and today rebased after rc1. It would be part of rc2... Thank you! Regards, Sekhar ___ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
