From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932526AbdIHI2c (ORCPT ); Fri, 8 Sep 2017 04:28:32 -0400 Received: from mx2.suse.de ([195.135.220.15]:36524 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753575AbdIHI2a (ORCPT ); Fri, 8 Sep 2017 04:28:30 -0400 Date: Fri, 08 Sep 2017 10:28:27 +0200 Message-ID: From: Takashi Iwai To: Sebastian Andrzej Siewior Cc: Takashi Sakamoto , alsa-devel@alsa-project.org, keescook@chromium.org, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, john.stultz@linaro.org, tglx@linutronix.de, anna-maria@linutronix.de, hch@lst.de Subject: Re: [alsa-devel] [PATCH 23/25 v3] ALSA/dummy: Replace tasklet with softirq hrtimer In-Reply-To: <4d532df1-1581-f390-322d-39de5595d26f@sakamocchi.jp> References: <20170901102537.8066-1-o-takashi@sakamocchi.jp> <19775981-a3f2-5f65-e934-bfe25db62a43@sakamocchi.jp> <20170905155351.2xmwyxrirndfwtgo@breakpoint.cc> <4cf46286-daf8-d52c-dacc-fa16052dcdb2@sakamocchi.jp> <20170905161820.jtysvxtfleunbbmf@breakpoint.cc> <4d532df1-1581-f390-322d-39de5595d26f@sakamocchi.jp> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.2 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 06 Sep 2017 06:30:03 +0200, Takashi Sakamoto wrote: > > On Sep 6 2017 01:18, Sebastian Andrzej Siewior wrote: > > From: Thomas Gleixner > > > > The tasklet is used to defer the execution of snd_pcm_period_elapsed() to > > the softirq context. Using the CLOCK_MONOTONIC_SOFT base invokes the timer > > callback in softirq context as well which renders the tasklet useless. > > > > Signed-off-by: Thomas Gleixner > > Signed-off-by: Anna-Maria Gleixner > > Cc: Jaroslav Kysela > > Cc: Takashi Iwai > > Cc: Takashi Sakamoto > > Cc: alsa-devel@alsa-project.org > > [o-takashi: avoid stall due to a call of hrtimer_cancel() on a callback > > of hrtimer] > > Signed-off-by: Takashi Sakamoto > > Signed-off-by: Sebastian Andrzej Siewior > > --- > > On 2017-09-06 01:05:43 [+0900], Takashi Sakamoto wrote: > >> As Iwai-san mentioned, in this function, .trigger can be called in two > >> cases; XRUN occurs and draining is done. Thus, let you change the comment as > >> 'In cases of XRUN and draining, this calls .trigger to stop PCM substream.'. > >> I'm sorry to trouble you. > >> > >> snd_pcm_period_elapsed() > >> ->snd_pcm_update_hw_ptr0() > >> ->snd_pcm_update_state() > >> ->snd_pcm_drain_done() > >> ... > >> ->.trigger(TRIGGER_STOP) > >> ->xrun() > >> ->snd_pcm_stop() > >> ... > >> ->.trigger(TRIGGER_STOP) > >> > > > > I think you asked me just to update the comment. Did I do it right? > > > > v2…v3: updated the comment as per Takashi Sakamoto's suggestion. > > v1…v2: merged Takashi Sakamoto fixup of the original patch into v2. > > > > sound/drivers/dummy.c | 25 +++++++++++-------------- > > 1 file changed, 11 insertions(+), 14 deletions(-) > > This Looks good to me. I did quick test and confirmed that it brings > no stalls. > > Tested-by: Takashi Sakamoto I suppose you'd apply all together in some tree like tip or whatever? In anyway, feel free to take my ack for this patch: Reviewed-by: Takashi Iwai Thanks! Takashi