From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79C0BC433DF for ; Wed, 10 Jun 2020 14:12:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51AAC2067B for ; Wed, 10 Jun 2020 14:12:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729759AbgFJOMj (ORCPT ); Wed, 10 Jun 2020 10:12:39 -0400 Received: from mga14.intel.com ([192.55.52.115]:34281 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727022AbgFJOMj (ORCPT ); Wed, 10 Jun 2020 10:12:39 -0400 IronPort-SDR: iQw7qB8FZPr5J8lFO0Ye9tmuq5h7XIpChO0/kp/8aLNKVwy4tf7FeKqXLwwoIjrbEktLljO+fy 2ZKwTM6uV5Vw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2020 07:12:39 -0700 IronPort-SDR: fKrJXsTqhlPXdaj5uo+Plq6f24Ee0V34xRBDERFPAU1oT+dwqd1TjgEWVneFvEOvOqdcHz0O1c x2BU4QuL/X4A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,496,1583222400"; d="scan'208";a="473350013" Received: from opolat-mobl.amr.corp.intel.com (HELO [10.251.2.3]) ([10.251.2.3]) by fmsmga006.fm.intel.com with ESMTP; 10 Jun 2020 07:12:38 -0700 Subject: Re: [RFC PATCH] ALSA: compress: Fix gapless playback state machine To: Srinivas Kandagatla , vkoul@kernel.org Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, tiwai@suse.com, broonie@kernel.org References: <20200610100729.362-1-srinivas.kandagatla@linaro.org> From: Pierre-Louis Bossart Message-ID: <694dd437-3453-7328-f544-28106c1c366d@linux.intel.com> Date: Wed, 10 Jun 2020 07:56:05 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200610100729.362-1-srinivas.kandagatla@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/10/20 5:07 AM, Srinivas Kandagatla wrote: > For gapless playback call to snd_compr_drain_notify() after > partial drain should put the state to SNDRV_PCM_STATE_RUNNING > rather than SNDRV_PCM_STATE_SETUP as the driver is ready to > process the buffers for new track. > > With existing code, if we are playing 3 tracks in gapless, after The gapless playback only deals with transitions between two tracks of identical format. I am not sure what the reference to 3 tracks means. > partial drain finished on previous track 1 the state is set to > SNDRV_PCM_STATE_SETUP which is then moved to SNDRV_PCM_STATE_PREPARED > after data write. With this state calls to snd_compr_next_track() and > few other calls will fail as they expect the state to be in > SNDRV_PCM_STATE_RUNNING. > > Here is the sequence of events and state transitions: > > 1. set_params (Track 1), state = SNDRV_PCM_STATE_SETUP > 2. set_metadata (Track 1), no state change, state = SNDRV_PCM_STATE_SETUP > 3. fill and trigger start (Track 1), state = SNDRV_PCM_STATE_RUNNING > 4. set_next_track (Track 2), state = SNDRV_PCM_STATE_RUNNING > 5. partial_drain (Track 1), state = SNDRV_PCM_STATE_SETUP > 6 snd_compr_drain_notify (Track 1), state = SNDRV_PCM_STATE_SETUP > 7. fill data (Track 2), state = SNDRV_PCM_STATE_PREPARED > 8. set_metadata (Track 3), no state change, state = SNDRV_PCM_STATE_PREPARED > 9. set_next_track (Track 3), !! FAILURE as state != SNDRV_PCM_STATE_RUNNING > > Fixes: f44f2a5417b2 ("ALSA: compress: fix drain calls blocking other compress functions (v6)") > Signed-off-by: Srinivas Kandagatla > --- > > I wonder who did gapless work on upstream so far? IIRC the only users of gapless playback are Android platforms, where the HAL deals with the transitions. I am not aware of any plain vanilla Linux solution. > > include/sound/compress_driver.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h > index 6ce8effa0b12..eabac33864c2 100644 > --- a/include/sound/compress_driver.h > +++ b/include/sound/compress_driver.h > @@ -182,7 +182,7 @@ static inline void snd_compr_drain_notify(struct snd_compr_stream *stream) > if (snd_BUG_ON(!stream)) > return; > > - stream->runtime->state = SNDRV_PCM_STATE_SETUP; > + stream->runtime->state = SNDRV_PCM_STATE_RUNNING; > > wake_up(&stream->runtime->sleep); > } >