From patchwork Tue Jul 30 19:53:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Edmund Raile X-Patchwork-Id: 815679 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 (unknown [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 A300BC3DA7F for ; Wed, 31 Jul 2024 08:55:53 +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 2C2412DB8; Wed, 31 Jul 2024 10:55:37 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 2C2412DB8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1722416147; bh=cfL8K8oOZTus+Z0CZyjYAFSnbMx9FZoKUDm75n+8bXs=; h=Date:To:From:Cc:Subject:List-Id:List-Archive:List-Help:List-Owner: List-Post:List-Subscribe:List-Unsubscribe:From; b=Q5ez/fJIs7GbHplcfTpgOyMKYXJtlbrutUhqO2D1cALL8qkwJtYSSKzkeFJv3lxZG sd739K64O8NwWGAoLhZHFt0jBg/0X7e7oPuO0VDX4brAUQSAjG9p7HSA8hABTzTfJX V3CktUaqPHqx5mQr7fzlPh3IhxJViNPM+QJKSavE= Received: by alsa1.perex.cz (Postfix, from userid 50401) id C108BF89710; Wed, 31 Jul 2024 10:50:40 +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 08349F89717; Wed, 31 Jul 2024 10:50:28 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 3134BF80579; Tue, 30 Jul 2024 21:58:55 +0200 (CEST) Received: from mail-40135.protonmail.ch (mail-40135.protonmail.ch [185.70.40.135]) (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 6E4F7F800E3 for ; Tue, 30 Jul 2024 21:53:28 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 6E4F7F800E3 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key, unprotected) header.d=protonmail.com header.i=@protonmail.com header.a=rsa-sha256 header.s=protonmail3 header.b=c712wpgT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1722369207; x=1722628407; bh=JZsQJ3qPV9zRVIItVT1nb+wNyCmtfkYU71yuifettk0=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=c712wpgTuLcKOnZ6Ilthadkwkt1KO3vAANuOiLHoMICjcLnj326Cgt5d8FS+DENWl 85TcTm0KPeR03brt0p191vqPATGzJNu7BL5hiMHv4EOEpxeSnIi0yjmZHk2TiEYmvw p4VVzQPnmbHrenJ604XI19Vk+IOzXkZ6trOntpG0k9/oCOFBp1TmGpe8uKgnr4zYbT /yzgstI8zHntFFbO0JiSIY1O7Ig7IKxoi3t6gCkk5KNQoWXZMQHmmpCC9p5lP/3ehP B2NFdh1cHJffWZ3iP64Ltz0p6A2UriBU7cZI+mssmCF46rEDPBSrD7kSy25jPEeoAR G9PkSbp8Vhk/A== Date: Tue, 30 Jul 2024 19:53:23 +0000 To: o-takashi@sakamocchi.jp, clemens@ladisch.de From: Edmund Raile Cc: tiwai@suse.com, alsa-devel@alsa-project.org, linux-sound@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v4 0/2] ALSA: firewire-lib: restore process context workqueue to prevent deadlock Message-ID: <20240730195318.869840-1-edmund.raile@protonmail.com> Feedback-ID: 43016623:user:proton X-Pm-Message-ID: 10fe8f538ef80dff132c856927b6dd56a60806b0 MIME-Version: 1.0 X-MailFrom: edmund.raile@protonmail.com X-Mailman-Rule-Hits: nonmember-moderation 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 Message-ID-Hash: V7Z24ROLV57VDMADUK2NGKHBDIIJQRTK X-Message-ID-Hash: V7Z24ROLV57VDMADUK2NGKHBDIIJQRTK X-Mailman-Approved-At: Wed, 31 Jul 2024 08:50:13 +0000 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: This patchset serves to prevent an AB/BA deadlock: thread 0: * (lock A) acquire substream lock by snd_pcm_stream_lock_irq() in snd_pcm_status64() * (lock B) wait for tasklet to finish by calling tasklet_unlock_spin_wait() in tasklet_disable_in_atomic() in ohci_flush_iso_completions() of ohci.c thread 1: * (lock B) enter tasklet * (lock A) attempt to acquire substream lock, waiting for it to be released: snd_pcm_stream_lock_irqsave() in snd_pcm_period_elapsed() in update_pcm_pointers() in process_ctx_payloads() in process_rx_packets() of amdtp-stream.c ? tasklet_unlock_spin_wait ohci_flush_iso_completions firewire_ohci amdtp_domain_stream_pcm_pointer snd_firewire_lib snd_pcm_update_hw_ptr0 snd_pcm snd_pcm_status64 snd_pcm ? native_queued_spin_lock_slowpath _raw_spin_lock_irqsave snd_pcm_period_elapsed snd_pcm process_rx_packets snd_firewire_lib irq_target_callback snd_firewire_lib handle_it_packet firewire_ohci context_tasklet firewire_ohci The issue has been reported as a regression of kernel 5.14: Link: https://lore.kernel.org/regressions/kwryofzdmjvzkuw6j3clftsxmoolynljztxqwg76hzeo4simnl@jn3eo7pe642q/T/#u ("[REGRESSION] ALSA: firewire-lib: snd_pcm_period_elapsed deadlock with Fireface 800") Commit 7ba5ca32fe6e ("ALSA: firewire-lib: operate for period elapse event in process context") removed the process context workqueue from amdtp_domain_stream_pcm_pointer() and update_pcm_pointers() to remove its overhead. Commit b5b519965c4c ("ALSA: firewire-lib: obsolete workqueue for period update") belongs to the same patch series and removed the now-unused workqueue entirely. Though being observed on RME Fireface 800, this issue would affect all Firewire audio interfaces using ohci amdtp + pcm streaming. ALSA streaming, especially under intensive CPU load will reveal this issue the soonest due to issuing more hardIRQs, with time to occurrence ranging from 2 secons to 30 minutes after starting playback. to reproduce the issue: direct ALSA playback to the device: mpv --audio-device=alsa/sysdefault:CARD=Fireface800 Spor-Ignition.flac Time to occurrence: 2s to 30m Likelihood increased by: - high CPU load stress --cpu $(nproc) - switching between applications via workspaces tested with i915 in Xfce PulsaAudio / PipeWire conceal the issue as they run PCM substream without period wakeup mode, issuing less hardIRQs. Cc: stable@vger.kernel.org Backport note: Also applies to and fixes on (tested): 6.10.2, 6.9.12, 6.6.43, 6.1.102, 5.15.164 Edmund Raile (2): Revert "ALSA: firewire-lib: obsolete workqueue for period update" Revert "ALSA: firewire-lib: operate for period elapse event in process context" sound/firewire/amdtp-stream.c | 38 ++++++++++++++++++++++------------- sound/firewire/amdtp-stream.h | 1 + 2 files changed, 25 insertions(+), 14 deletions(-)