From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751547AbeAPK2A (ORCPT + 1 other); Tue, 16 Jan 2018 05:28:00 -0500 Received: from terminus.zytor.com ([65.50.211.136]:35501 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbeAPK16 (ORCPT ); Tue, 16 Jan 2018 05:27:58 -0500 Date: Tue, 16 Jan 2018 02:23:12 -0800 From: tip-bot for Thomas Gleixner Message-ID: Cc: anna-maria@linutronix.de, tiwai@suse.de, tglx@linutronix.de, hch@lst.de, o-takashi@sakamocchi.jp, tiwai@suse.com, torvalds@linux-foundation.org, john.stultz@linaro.org, linux-kernel@vger.kernel.org, hpa@zytor.com, peterz@infradead.org, mingo@kernel.org, perex@perex.cz Reply-To: perex@perex.cz, john.stultz@linaro.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, hpa@zytor.com, peterz@infradead.org, mingo@kernel.org, hch@lst.de, tglx@linutronix.de, o-takashi@sakamocchi.jp, tiwai@suse.com, tiwai@suse.de, anna-maria@linutronix.de In-Reply-To: <20171221104205.7269-35-anna-maria@linutronix.de> References: <20171221104205.7269-35-anna-maria@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:timers/core] ALSA/dummy: Replace tasklet with softirq hrtimer Git-Commit-ID: b03bbbe08ff04d80136b6aac152954ef308a4909 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Commit-ID: b03bbbe08ff04d80136b6aac152954ef308a4909 Gitweb: https://git.kernel.org/tip/b03bbbe08ff04d80136b6aac152954ef308a4909 Author: Thomas Gleixner AuthorDate: Thu, 21 Dec 2017 11:42:03 +0100 Committer: Ingo Molnar CommitDate: Tue, 16 Jan 2018 09:51:22 +0100 ALSA/dummy: Replace tasklet with softirq hrtimer The tasklet is used to defer the execution of snd_pcm_period_elapsed() to the softirq context. Using the HRTIMER_MODE_SOFT mode invokes the timer callback in softirq context as well which renders the tasklet useless. [o-takashi: avoid stall due to a call of hrtimer_cancel() on a callback of hrtimer] Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Takashi Iwai Cc: Christoph Hellwig Cc: Jaroslav Kysela Cc: John Stultz Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Takashi Iwai Cc: Takashi Sakamoto Cc: alsa-devel@alsa-project.org Cc: keescook@chromium.org Link: http://lkml.kernel.org/r/20171221104205.7269-35-anna-maria@linutronix.de Signed-off-by: Ingo Molnar --- sound/drivers/dummy.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c index 7b2b1f7..6ad2ff5 100644 --- a/sound/drivers/dummy.c +++ b/sound/drivers/dummy.c @@ -375,17 +375,9 @@ struct dummy_hrtimer_pcm { ktime_t period_time; atomic_t running; struct hrtimer timer; - struct tasklet_struct tasklet; struct snd_pcm_substream *substream; }; -static void dummy_hrtimer_pcm_elapsed(unsigned long priv) -{ - struct dummy_hrtimer_pcm *dpcm = (struct dummy_hrtimer_pcm *)priv; - if (atomic_read(&dpcm->running)) - snd_pcm_period_elapsed(dpcm->substream); -} - static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer) { struct dummy_hrtimer_pcm *dpcm; @@ -393,7 +385,14 @@ static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer) dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer); if (!atomic_read(&dpcm->running)) return HRTIMER_NORESTART; - tasklet_schedule(&dpcm->tasklet); + /* + * In cases of XRUN and draining, this calls .trigger to stop PCM + * substream. + */ + snd_pcm_period_elapsed(dpcm->substream); + if (!atomic_read(&dpcm->running)) + return HRTIMER_NORESTART; + hrtimer_forward_now(timer, dpcm->period_time); return HRTIMER_RESTART; } @@ -403,7 +402,7 @@ static int dummy_hrtimer_start(struct snd_pcm_substream *substream) struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data; dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer); - hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL); + hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL_SOFT); atomic_set(&dpcm->running, 1); return 0; } @@ -413,14 +412,14 @@ static int dummy_hrtimer_stop(struct snd_pcm_substream *substream) struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data; atomic_set(&dpcm->running, 0); - hrtimer_cancel(&dpcm->timer); + if (!hrtimer_callback_running(&dpcm->timer)) + hrtimer_cancel(&dpcm->timer); return 0; } static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm) { hrtimer_cancel(&dpcm->timer); - tasklet_kill(&dpcm->tasklet); } static snd_pcm_uframes_t @@ -465,12 +464,10 @@ static int dummy_hrtimer_create(struct snd_pcm_substream *substream) if (!dpcm) return -ENOMEM; substream->runtime->private_data = dpcm; - hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT); dpcm->timer.function = dummy_hrtimer_callback; dpcm->substream = substream; atomic_set(&dpcm->running, 0); - tasklet_init(&dpcm->tasklet, dummy_hrtimer_pcm_elapsed, - (unsigned long)dpcm); return 0; }