From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: Re: [PATCH 1/4] ASoC: compress: Pass error out of soc_compr_pointer Date: Fri, 11 Mar 2016 11:13:11 +0000 Message-ID: <20160311111311.GI1490@localhost.localdomain> References: <1457606694-10985-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> <20160311074843.GV11154@localhost> <20160311100425.GH1490@localhost.localdomain> <20160311103747.GZ11154@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx0a-001ae601.pphosted.com (mx0a-001ae601.pphosted.com [67.231.149.25]) by alsa0.perex.cz (Postfix) with ESMTP id 0ED2A2610A6 for ; Fri, 11 Mar 2016 12:13:32 +0100 (CET) Content-Disposition: inline In-Reply-To: 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: Takashi Iwai Cc: alsa-devel@alsa-project.org, Vinod Koul , patches@opensource.wolfsonmicro.com, lgirdwood@gmail.com, broonie@kernel.org List-Id: alsa-devel@alsa-project.org On Fri, Mar 11, 2016 at 11:39:11AM +0100, Takashi Iwai wrote: > On Fri, 11 Mar 2016 11:37:47 +0100, > Vinod Koul wrote: > > > > On Fri, Mar 11, 2016 at 10:04:25AM +0000, Charles Keepax wrote: > > > On Fri, Mar 11, 2016 at 01:18:43PM +0530, Vinod Koul wrote: > > > > On Thu, Mar 10, 2016 at 10:44:51AM +0000, Charles Keepax wrote: > > > > > The soc_compr_pointer does not correctly pass any errors returned by the > > > > > driver callback back up the stack. This patch corrects this issue. > > > > > > > > Should we do that :) I am not too sure. Pointer query is supposed to read > > > > the current value and return. You are trying to indicate that stream has > > > > gone bad which is not the same as read faced an error... > > > > > > > > Also please use cover letter for these things to describe problem you are > > > > trying to solve. > > > > > > Apologies for not doing so, I had been viewing this as more of a > > > simple oversight in the framework rather than a design choice. > > > > > > The problem I am looking at is the DSP suffers an unrecoverable > > > error. We can find out about this error in our driver because the > > > DSP returns some error status to us. This is fine if user-space > > > is doing a read as reads return error status back to user-space > > > so the user can find out that things have gone bad. However, if > > > user-space is doing an avail request there is no path for the > > > error to come back up to user-space. The pointer request returns > > > zero available data, so a read never happens and we basically > > > just end up sitting waiting for data on a stream that we know > > > full well has died. > > > > So this confirms my hunch and we should then notify core of error by stopping > > the stream properly and then return error on poll/pointer query. > > > > So cna try this untested patch, whcih includes a hack for stopped state. We > > don't seem to have a stopped state in ALSA, that bit would need refinement > > In PCM, the stopped state is either SETUP/PREPARE or XRUN. > > > Takashi Thanks guys, I will take a look at all this and look at respinning the series. Thanks, Charles