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: stable@xxxxxxxxxxxxxxx # v3.12.x+ > > Cc: Joel Fernandes <joelf@xxxxxx> > > Acked-by: Joel Fernandes <joelf@xxxxxx> > > Tested-by: Jon Ringle <jringle@xxxxxxxxxxxxx> > > Tested-by: Alexander Holler <holler@xxxxxxxxxxxxx> > > Reported-by: Jon Ringle <jringle@xxxxxxxxxxxxx> > > Signed-off-by: Sekhar Nori <nsekhar@xxxxxx> > > 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 -- -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
