From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolin Chen Subject: Re: fsl_ssi.c: Getting channel slips with fsl_ssi.c in TDM (network) mode. Date: Tue, 27 Oct 2015 13:11:02 -0700 Message-ID: <20151027201101.GA9527@Asurada-CZ80> References: <5625EF02.30602@invoxia.com> <56273F75.2040702@invoxia.com> <20151027071344.GC25728@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f42.google.com (mail-pa0-f42.google.com [209.85.220.42]) by alsa0.perex.cz (Postfix) with ESMTP id 1A2B926061B for ; Tue, 27 Oct 2015 21:11:09 +0100 (CET) Received: by pasz6 with SMTP id z6so231736519pas.2 for ; Tue, 27 Oct 2015 13:11:07 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20151027071344.GC25728@pengutronix.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Markus Pargmann Cc: Fabio Estevam , "alsa-devel@alsa-project.org" , "shawn.guo@linaro.org" , "arnaud.mouiche@invoxia.com" , Caleb Crome List-Id: alsa-devel@alsa-project.org On Tue, Oct 27, 2015 at 08:13:44AM +0100, Markus Pargmann wrote: > > So, the dma priority doesn't seem to be the issue. It's now set in > > the device tree, and strangely it's set to priority 0 (the highest) > > along with the UARTS. priority 0 is just the highest in the device > > tree -- it gets remapped to priority 3 in the sdma driver. the DT > > exposes only 3 levels of DMA priority, low, medium, and high. I > > created a new level that maps to DMA priroity 7 (the highest in the > > hardware), but still got the problem. > > > > So, still something unknown causing dma to miss samples. must be in > > the dma ISR I would assume. I guess it's time to look into that. > Cc Nicolin, Fabio, Shawn > > Perhaps you have an idea about this? Off the top of my head: 1) Enable TUE0, TUE1, ROE0, ROE1 to see if there is any IRQ trigged. 2) Set the watermarks for both TX and RX to 8 while using burst sizes of 6. It'd be nicer to provisionally set these numbers using hard code than your current change depending on fifo_depth as it might be an odd value. 3) Try to enlarge the ALSA period size in the asound.conf or passing parameters when you do the playback/capture so that the number of interrupts from SDMA may reduce. You may also see if the reproducibility is somehow reduced or not. Nicolin