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 Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 87B7CCD3431 for ; Wed, 4 Sep 2024 09:29:53 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 34629B60; Wed, 4 Sep 2024 11:29:41 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 34629B60 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1725442191; bh=3DYh1e2GuK4obzNV7376qpnjHHx8i2d0t9UfuJpCnq4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:List-Id: List-Archive:List-Help:List-Owner:List-Post:List-Subscribe: List-Unsubscribe:From; b=O0v613Dh3cpOo1DlO0R1IMITRcYIxsrujTNi6VbIpJBeliY+vWUvgIwWtilDveV2x nuQM/b3cZtKwg8ANnOTCvM3QhUmLppDGoBXXYOZo2sSIcfZJqi9qyDDLqgvLaSz7tQ Zp8o52Ux76O3oy5ovSYmIklpDHqZEfKL4Wyouc80= Received: by alsa1.perex.cz (Postfix, from userid 50401) id 948B3F805AB; Wed, 4 Sep 2024 11:29:19 +0200 (CEST) Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 38177F8059F; Wed, 4 Sep 2024 11:29:19 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 0CB1EF80199; Wed, 4 Sep 2024 11:29:14 +0200 (CEST) Received: from mail1.perex.cz (mail1.perex.cz [77.48.224.245]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id DECB7F80027 for ; Wed, 4 Sep 2024 11:29:11 +0200 (CEST) Received: from mail1.perex.cz (localhost [127.0.0.1]) by smtp1.perex.cz (Perex's E-mail Delivery System) with ESMTP id 14D382EB9; Wed, 4 Sep 2024 11:29:10 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.perex.cz 14D382EB9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=perex.cz; s=default; t=1725442150; bh=u6W8y2ZiH4biuWfjJrGxEW01U4Sjv0XzXI3J43x/O5o=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rM1SrenwfwHqyhwqccNr3DQdWL/3qY4sAiYsVqWNBEgKbugx8OJydxTaYO6ND2e/x cpm3cDx2CBDkszlVMV4/+FRRfjZSBoHgehMChA25h61jZViF2Ltei1jyWp8nLXyyJf Y/vF7JcN+DEQ8tvRInDyyBKYs+cB88vCtTRl2HHw= Received: from [192.168.100.98] (unknown [192.168.100.98]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: perex) by mail1.perex.cz (Perex's E-mail Delivery System) with ESMTPSA; Wed, 4 Sep 2024 11:29:05 +0200 (CEST) Message-ID: <403ab960-ee4f-404a-81ab-e63d4a7f7ef9@perex.cz> Date: Wed, 4 Sep 2024 11:29:05 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Suspend/resume Issue on pcm_dmix.c in alsa-lib To: Chancel Liu , Takashi Iwai Cc: "alsa-devel@alsa-project.org" , "S.J. Wang" References: <87msky1bqh.wl-tiwai@suse.de> Content-Language: en-US From: Jaroslav Kysela Autocrypt: addr=perex@perex.cz; keydata= xsFNBFvNeCsBEACUu2ZgwoGXmVFGukNPWjA68/7eMWI7AvNHpekSGv3z42Iy4DGZabs2Jtvk ZeWulJmMOh9ktP9rVWYKL9H54gH5LSdxjYYTQpSCPzM37nisJaksC8XCwD4yTDR+VFCtB5z/ E7U0qujGhU5jDTne3dZpVv1QnYHlVHk4noKxLjvEQIdJWzsF6e2EMp4SLG/OXhdC9ZeNt5IU HQpcKgyIOUdq+44B4VCzAMniaNLKNAZkTQ6Hc0sz0jXdq+8ZpaoPEgLlt7IlztT/MUcH3ABD LwcFvCsuPLLmiczk6/38iIjqMtrN7/gP8nvZuvCValLyzlArtbHFH8v7qO8o/5KXX62acCZ4 aHXaUHk7ahr15VbOsaqUIFfNxpthxYFuWDu9u0lhvEef5tDWb/FX+TOa8iSLjNoe69vMCj1F srZ9x2gjbqS2NgGfpQPwwoBxG0YRf6ierZK3I6A15N0RY5/KSFCQvJOX0aW8TztisbmJvX54 GNGzWurrztj690XLp/clewmfIUS3CYFqKLErT4761BpiK5XWUB4oxYVwc+L8btk1GOCOBVsp 4xAVD2m7M+9YKitNiYM4RtFiXwqfLk1uUTEvsaFkC1vu3C9aVDn3KQrZ9M8MBh/f2c8VcKbN njxs6x6tOdF5IhUc2E+janDLPZIfWDjYJ6syHadicPiATruKvwARAQABzSBKYXJvc2xhdiBL eXNlbGEgPHBlcmV4QHBlcmV4LmN6PsLBjgQTAQgAOBYhBF7f7LZepM3UTvmsRTCsxHw/elMJ BQJbzXgrAhsDBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAAoJEDCsxHw/elMJDGAP/ReIRiRw lSzijpsGF/AslLEljncG5tvb/xHwCxK5JawIpViwwyJss06/IAvdY5vn5AdfUfCl2J+OakaR VM/hdHjCYNu4bdBYZQBmEiKsPccZG2YFDRudEmiaoaJ1e8ZsiA3rSf4SiWWsbcBOYHr/unTf 4KQsdUHzPUt8Ffi9HrAFzI2wjjiyV5yUGp3x58ZypAIMcKFtA1aDwhA6YmQ6lb8/bC0LTC6l cAAS1tj7YF5nFfXsodCOKK5rKf5/QOF0OCD2Gy+mGLNQnq6S+kD+ujQfOLaUHeyfcNBEBxda nZID7gzd65bHUMAeWttZr3m5ESrlt2SaNBddbN7NVpVa/292cuwDCLw2j+fAZbiVOYyqMSY4 LaNqmfa0wJAv30BMKeRAovozJy62j0AnntqrvtDqqvuXgYirj2BEDxx0OhZVqlI8o5qB6rA5 Pfp2xKRE8Fw3mASYRDNad08JDhJgsR/N5JDGbh4+6sznOA5J63TJ+vCFGM37M5WXInrZJBM3 ABicmpClXn42zX3Gdf/GMM3SQBrIriBtB9iEHQcRG/F+kkGOY4QDi4BZxo45KraANGmCkDk0 +xLZVfWh8YOBep+x2Sf83up5IMmIZAtYnxr77VlMYHDWjnpFnfuja+fcnkuzvvy7AHJZUO1A aKexwcBjfTxtlX4BiNoK+MgrjYywzsFNBFvNeCsBEACb8FXFMOw1g+IGVicWVB+9AvOLOhqI FMhUuDWmlsnT8B/aLxcRVUTXoNgJpt0y0SpWD3eEJOkqjHuvHfk+VhKWDsg6vlNUmF1Ttvob 18rce0UH1s+wlE8YX8zFgODbtRx8h/BpykwnuWNTiotu9itlE83yOUbv/kHOPUz4Ul1+LoCf V2xXssYSEnNr+uUG6/xPnaTvKj+pC7YCl38Jd5PgxsP3omW2Pi9T3rDO6cztu6VvR9/vlQ8Z t0p+eeiGqQV3I+7k+S0J6TxMEHI8xmfYFcaVDlKeA5asxkqu5PDZm3Dzgb0XmFbVeakI0be8 +mS6s0Y4ATtn/D84PQo4bvYqTsqAAJkApEbHEIHPwRyaXjI7fq5BTXfUO+++UXlBCkiH8Sle 2a8IGI1aBzuL7G9suORQUlBCxy+0H7ugr2uku1e0S/3LhdfAQRUAQm+K7NfSljtGuL8RjXWQ f3B6Vs7vo+17jOU7tzviahgeRTcYBss3e264RkL62zdZyyArbVbK7uIU6utvv0eYqG9cni+o z7CAe7vMbb5KfNOAJ16+znlOFTieKGyFQBtByHkhh86BQNQn77aESJRQdXvo5YCGX3BuRUaQ zydmrgwauQTSnIhgLZPv5pphuKOmkzvlCDX+tmaCrNdNc+0geSAXNe4CqYQlSnJv6odbrQlD Qotm9QARAQABwsF2BBgBCAAgFiEEXt/stl6kzdRO+axFMKzEfD96UwkFAlvNeCsCGwwACgkQ MKzEfD96Uwlkjg/+MZVS4M/vBbIkH3byGId/MWPy13QdDzBvV0WBqfnr6n99lf7tKKp85bpB y7KRAPtXu+9WBzbbIe42sxmWJtDFIeT0HJxPn64l9a1btPnaILblE1mrfZYAxIOMk3UZA3PH uFdyhQDJbDGi3LklDhsJFTAhBZI5xMSnqhaMmWCL99OWwfyJn2omp8R+lBfAJZR31vW6wzsj ssOvKIbgBpV/o3oGyAofIXPYzhY+jhWgOYtiPw9bknu748K+kK3fk0OeEG6doO4leB7LuWig dmLZkcLlJzSE6UhEwHZ8WREOMIGJnMF51WcF0A3JUeKpYYEvSJNDEm7dRtpb0x/Y5HIfrg5/ qAKutAYPY7ClQLu5RHv5uqshiwyfGPaiE8Coyphvd5YbOlMm3mC/DbEstHG7zA89fN9gAzsJ 0TFL5lNz1s/fo+//ktlG9H28EHD8WOwkpibsngpvY+FKUGfJgIxpmdXVOkiORWQpndWyRIqw k8vz1gDNeG7HOIh46GnKIrQiUXVzAuUvM5vI9YaW3YRNTcn3pguQRt+Tl9Y6G+j+yvuLL173 m4zRUU6DOygmpQAVYSOJvKAJ07AhQGaWAAi5msM6BcTU4YGcpW7FHr6+xaFDlRHzf1lkvavX WoxP1IA1DFuBMeYMzfyi4qDWjXc+C51ZaQd39EulYMh+JVaWRoY= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Message-ID-Hash: 6HEBI45X5XBXHUGHFLWP7LYAQPFE52RJ X-Message-ID-Hash: 6HEBI45X5XBXHUGHFLWP7LYAQPFE52RJ X-MailFrom: perex@perex.cz X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.9 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 04. 09. 24 11:07, Chancel Liu wrote: > Hi Takashi, > > Thanks for your reply and suggestions. Finally we have found the root cause. > Seems it's related to both drivers and alsa-lib. > > When two dmix clients run in parallel we get two direct dmix instances. > 1st dmix instance: > snd_pcm_dmix_open() > snd_pcm_direct_initialize_slave() > save_slave_setting() > Since the driver we are using has SND_PCM_INFO_RESUME flag, dmix->spcm->info > has this flag. Then this flag is cleared in dmix->shmptr->s.info. > > 2nd dmix instance: > snd_pcm_dmix_open() > snd_pcm_direct_open_secondary_client() > copy_slave_setting() > 2nd dmix->spcm->info is copied from dmix->shmptr->s.info so it doesn' has this > flag. > > If 1st dmix instance resumes firstly it should implement recovery of slave pcm > in snd_pcm_direct_slave_recover(). Because 1st dmix->spcm->info has > SND_PCM_INFO_RESUMEļ¼Œsnd_pcm_resume(direct->spcm) can be called correctly to > resume slave pcm. > > However if 2nd dmix instance resumes firstly, snd_pcm_resume(direct->spcm) will > not be called because it's spcm->info doesn't has SND_PCM_INFO_RESUME flag. The > 1st dmix instance assumes someone else already did recovery so > snd_pcm_resume(direct->spcm) won't be called neither. In result the slave pcm > fails to resume. The snd_pcm_direct_slave_recover() function should be called for both dmix instances. It calls snd_pcm_prepare() for the "driver" PCM, so the driver should recover from suspend in this case, too. See the "some buggy drivers" comment in snd_pcm_direct_slave_recover(). It looks like a driver issue, the "resume" flag mangling is just a workaround. > SND_PCM_INFO_RESUME flag has impact on the flow of dmix resume. In my opinion > the first resumed dmix instance should make sure slave pcm can be recovered > properly no matter it's the first opened instance or secondary opened instance. > Do you know why the secondary opened instance clear the SND_PCM_INFO_RESUME > flag? Can we do the following modification? > > diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c > @@ -1183,8 +1226,6 @@ static void save_slave_setting(snd_pcm_direct_t *dmix, snd_pcm_t *spcm) > COPY_SLAVE(buffer_time); > COPY_SLAVE(sample_bits); > COPY_SLAVE(frame_bits); > - > - dmix->shmptr->s.info &= ~SND_PCM_INFO_RESUME; Another option is to fix the buggy drivers and remove the workround (or make it configurable) from alsa-lib (revert commit 6d1d620eadf32c6d963468ce56ff52cc3a2f32e2). Jaroslav -- Jaroslav Kysela Linux Sound Maintainer; ALSA Project; Red Hat, Inc.