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: 13747842 Received: from mail-40135.protonmail.ch (mail-40135.protonmail.ch [185.70.40.135]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1A0418C91F for ; Tue, 30 Jul 2024 19:53:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.70.40.135 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722369212; cv=none; b=moXv7ZoBeMqhas9ZhfaM1u14PDml60ECQQQ8wKAaUkRexXz0/0OGGDlYSqrXkT3vc8xERBusUNNNmfQaeU+CMOYGigUjA4QZR21HCmLot4yEf3jdYloKGfZpLAHlVN+XyGFEhBjwc7tcCWmJaxPsWs4A9TrDeVWUKUsMPaQpLLI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722369212; c=relaxed/simple; bh=cfL8K8oOZTus+Z0CZyjYAFSnbMx9FZoKUDm75n+8bXs=; h=Date:To:From:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=SWFdlYgabuqOOe03sOUnm+UFVGtA/S589G2oFItT7/7+bKDLlw6QvkB8ftSmSyztReBhR7vNfvs4JVrI6wcy5jDHoz6FgiO5g3a2NlrKvCZFaT0XjKWFAAKGpM96+d/ojel0VINJK9/19/1mzGSlndeJULAXwpiFKu7VlNOV4hM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=protonmail.com; spf=pass smtp.mailfrom=protonmail.com; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com header.b=c712wpgT; arc=none smtp.client-ip=185.70.40.135 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=protonmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=protonmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com 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 Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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(-) Reviewed-by: Takashi Sakamoto