From patchwork Sun Jul 28 12:30:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Edmund Raile X-Patchwork-Id: 815685 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 96F55C3DA7F for ; Wed, 31 Jul 2024 08:52:34 +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 133862C78; Wed, 31 Jul 2024 10:52:18 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 133862C78 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1722415948; bh=MAxeEGmgS9693J0PQhUIRbfqko2MsleF4u/sBRGsb4Y=; h=Date:To:From:Cc:Subject:List-Id:List-Archive:List-Help:List-Owner: List-Post:List-Subscribe:List-Unsubscribe:From; b=ALJN+gVTZwINwZv9wXz5lPEp6I7CiWr01ItkcsuR5tiNJNeHQ0rp8Wz9HhICvcYqm v4GR6TZdluR/+VMD6IXU16royqEM6wc6GOFfvsp4ftyDNxEy7zwsE7Y5dNdSWoI3Tz Bmuy/PjU2VIcNqIU0kWdYu0JsVd3Iq/Sl9C4tERI= Received: by alsa1.perex.cz (Postfix, from userid 50401) id 33285F80709; Wed, 31 Jul 2024 10:49:46 +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 5432FF806EF; Wed, 31 Jul 2024 10:49:43 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 9B4EAF8057A; Sun, 28 Jul 2024 14:30:55 +0200 (CEST) Received: from mail-40132.protonmail.ch (mail-40132.protonmail.ch [185.70.40.132]) (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 B5597F8007E for ; Sun, 28 Jul 2024 14:30:52 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz B5597F8007E 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=IWZxJ5YD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1722169851; x=1722429051; bh=74jrJoeOKYDJalJmIabOoA19hszvpDADNvzc31C/j48=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=IWZxJ5YDL7Ce7juBsEy5OSPMznmEIgaAgmvapHjDzlImwKLcHLrrEoKzBgIfW5YdN V48cfG23FDwCwzrrPZs8aHZxPNLAAIHBBMZ03ku7C5e66JU/JSJSwJcTgUC4GsvUuQ ECTwsEbg6yRqJ5uab6snoarybnTc2J4y+Gby7YqzaoJ54hS6gVjREBAiNImL7wXFwS sapSzAjo1CrL1D7EcFaF7hxSeCSKU/Tr/y9l2LQrSPJVIwYTaiYR8Kt61lyo1bch6K /bTfUhPAyUbp29TSk+TQNpbGabhyTolAQHPQngciNHCYjrl2YcaAGQHfV2bg63cmHX Nsm5/QJa8zkLA== Date: Sun, 28 Jul 2024 12:30:47 +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, edmund.raile@protonmail.com, stable@vger.kernel.org Subject: [PATCH v2 0/2] ALSA: firewire-lib: restore process context workqueue to prevent deadlock Message-ID: <20240728123041.330216-1-edmund.raile@protonmail.com> Feedback-ID: 43016623:user:proton X-Pm-Message-ID: 500a5c58425b9882f4a46ffd67423ae483b9ae31 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: ZLXP2EKSLMIXX262GL3OE5SKJHNNYAH6 X-Message-ID-Hash: ZLXP2EKSLMIXX262GL3OE5SKJHNNYAH6 X-Mailman-Approved-At: Wed, 31 Jul 2024 08:49:10 +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 a deadlock between process context and softIRQ context: A. In the process context * (lock A) Acquiring spin_lock by snd_pcm_stream_lock_irq() in snd_pcm_status64() * (lock B) Then attempt to enter tasklet B. In the softIRQ context * (lock B) Enter tasklet * (lock A) Attempt to acquire spin_lock by snd_pcm_stream_lock_irqsave() in snd_pcm_period_elapsed() ? 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. 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): ALSA: firewire-lib: restore workqueue for process context ALSA: firewire-lib: prevent deadlock between process and softIRQ context sound/firewire/amdtp-stream.c | 36 ++++++++++++++++++++++------------- sound/firewire/amdtp-stream.h | 1 + 2 files changed, 24 insertions(+), 13 deletions(-)