From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [RFC v2] dmaengine: omap-dma: Start DMA without delay for cyclic channels Date: Mon, 8 Apr 2013 10:15:19 -0700 Message-ID: <20130408171519.GP10155@atomide.com> References: <1364987862-14597-1-git-send-email-peter.ujfalusi@ti.com> <51626D88.8020809@ti.com> <20130408170956.GX30923@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:42524 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S934558Ab3DHRPi (ORCPT ); Mon, 8 Apr 2013 13:15:38 -0400 Content-Disposition: inline In-Reply-To: <20130408170956.GX30923@n2100.arm.linux.org.uk> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Russell King - ARM Linux Cc: Peter Ujfalusi , Vinod Koul , Dan Williams , Jarkko Nikula , Santosh Shilimkar , Felipe Balbi , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Peter Meerwald * Russell King - ARM Linux [130408 10:15]: > On Mon, Apr 08, 2013 at 09:11:04AM +0200, Peter Ujfalusi wrote: > > Russell, > > > > On 04/03/2013 01:17 PM, Peter Ujfalusi wrote: > > > cyclic DMA is only used by audio which needs DMA to be started without a > > > delay. > > > If the DMA for audio is started using the tasklet we experience random > > > channel switch (to be more precise: channel shift). > > > > > > Reported-by: Peter Meerwald > > > Signed-off-by: Peter Ujfalusi > > > --- > > > Hi Russell, > > > > > > Instead of removing the tasklet we can identify the DMA channel used by audio > > > based on the cyclic flag of the channel. > > > I think this can be used as a short term solution to fix the audio channel shift > > > issue and later when we have the dynamic DMA channel allocation we can adjust > > > the code. > > > > Could you, please look at this patch? > > Now that I'm back from a short 4 day break, then yes, and the answer is > that it's fine. Who's handling the patch? I suggest Peter resend the patch with also Grant + Linus W cc:d so they can queue it unless there are other related patches pending somewhere else. Regards, Tony