From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Berg Subject: Re: [RFC/PATCH] Stop Apple i2s DMA gracefully Date: Mon, 06 Nov 2006 11:50:57 +0100 Message-ID: <1162810257.2762.19.camel@ux156> References: <17732.11228.441627.300383@cargo.ozlabs.ibm.com> <1162456168.3241.2.camel@ux156> <17738.26872.275355.217147@cargo.ozlabs.ibm.com> <1162508394.3381.4.camel@johannes.berg> <17743.4433.435455.686127@cargo.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sipsolutions.net (crystal.sipsolutions.net [195.210.38.204]) by alsa.jcu.cz (ALSA's E-mail Delivery System) with ESMTP id 31045242 for ; Mon, 6 Nov 2006 11:49:50 +0100 (MET) In-Reply-To: <17743.4433.435455.686127@cargo.ozlabs.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@lists.sourceforge.net Errors-To: alsa-devel-bounces@lists.sourceforge.net To: Paul Mackerras Cc: Takashi Iwai , alsa-devel@alsa-project.org, benjamin@sipsolutions.net List-Id: alsa-devel@alsa-project.org On Mon, 2006-11-06 at 21:41 +1100, Paul Mackerras wrote: > OK, this sounds like the suspend trigger should just abort the DMA, on > the basis that the hardware will get reset in the suspend/resume > process and so there will be no bytes queued up to cause trouble > later. I'll whip up a patch. I think we should cleanly stop the hardware in this case as well, for suspend to disk I think it can happen that we suspend the driver and then suspend is aborted. Not entirely sure about this though. Btw. What happens when we abort the DMA engine, reset the command pointer to a stop command, and start it again? Does it drain the FIFO properly? I'm thinking it should, but ... johannes ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642