From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.210.181 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794458147; b=Ic9HRzfDMZrhO9elrtz89Ta33HEKyzKaDurIYnXacR9DAPgFLBSMvxmodgXzZrC74zH3 vaxane5P5m8IZupuQm2smEUBOPL66zcqF952pADVeqh4CR4kp9oDkvTxU3wWhuvYZWmeK t4aHKk7hf77Wpl4MzQXomhHEn70IeedLhnx4N9ZW+FVYfmUtKWiu4wNKRrvS+sxA/iwp1 lg4XW0dYwYcNgO9K3a6xGSlrgjqgEcM8eDN0SBHU8CcX5rvOlZXVgL42+Yuwh4PE+IumA W8MaM+IKPCHSloangDcnYNi6ACcLiJnrEInUnBthiOuSci1edRK75C3notHGf5JQ9zA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794458147; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=MsI4m0uo6XJTpD5aQtetIa3TMpTeA9EBkJp0jkGREkg=; b=m0WJwGvXoE0MO9seDm1cbrkqE6AfbfEWbQuHXB6ZDiawPXS/MA5jK2qnorko+xO0KQIM Q+zYN2QXO6eUWa8/a62Ji2qz/UkxbPxtL7CImz3PTAFyJI7A93GaKzKV39QJZJVkhlsvU Lk5qWPl1zDY5CPU7KTrsz2saEFnlxtNfffRTA0dXNrYXw3b4E8tQUzy1Se4tj6xxRSk1I 9Js9jKKxdg1u7Id8isYUW/6g/xsL95YsrxyOH/WoR2hYMXxAVlu23uXG+f2krPB4WCcVd MruPHlhunEI4GAvVp8MGq/qEDPdCqGir1VBRO41yOdq2XepKej8QRCR0WjBNReJoCnw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=RXPbFD9y; arc=none smtp.remote-ip=209.85.210.181 Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 22DBE60A3810 for ; Thu, 12 Nov 2026 04:35:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 22DBE60A3810 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=RXPbFD9y Received: by mail-pf1-f181.google.com with SMTP id d2e1a72fcca58-8b3577deeb0so1908011b3a.3 for ; Wed, 11 Nov 2026 20:35:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794458146; x=1795062946; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=MsI4m0uo6XJTpD5aQtetIa3TMpTeA9EBkJp0jkGREkg=; b=RXPbFD9yu8ZpkTJf2Owp9lv5LazmyV8ye+cm1uU+UrysJhSNIVEwiJJ40qNH0KWShH 8Tn4STtkcPCCKK5Zyer59nnqgzoHmMF42+tGPzBwr69orsK5HDGVf6/3KBw+cglpDiMk Hpz6TSs6KQPQIjdavqI6TibzsQ12f1Z7wI2sc2V+gM2Y3obOrbOUXZXbCxpuoXAX9k/U AUgZiZFydhYpcDvMY8kClDqzBtuyZ29V7r8drMHe6+vitmKzlJUL7CTNBDZvIhjj6dFJ DrGo9CkW7+Jdk1hylUIoyNeO708UwkB3619PFxTE03WkUAC6qIf1I+Rs/7sHEhhzKwzz I3vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794458146; x=1795062946; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=MsI4m0uo6XJTpD5aQtetIa3TMpTeA9EBkJp0jkGREkg=; b=maC6+vI4FiDA3wteVK06W1eZzEn0GONOnd7yJz3wmMgIIk4zDye5rN2toxThsVvwzU XoNf7+WlWITjcd8IOBrcVvU3zFdl7oD5k6up2m1SWLaMNUC15HUSp/Tb/uexyDXvrSqV Ol2EEx9gQnGwy6t5j15WQxmYdtHhgWZFwW+IQvS4uvtCJ8gCkI7Kl0omQdLmLh/M/R0q MvPKYogW5/2WYebcbcuDlFWzPo5kL6yIhFjNG/iEXU71lP9eEpoIgBbWvU0cPCcpqPbV MtubqPObZ3YNMJZ7hEjkXz82skssDrJftWwGki/C1N8B8lpx4GlxVdBedd5FoIXQMP1t VdQg== X-Forwarded-Encrypted: i=1; AL+hErF8FgiKT3Ukls5UjirioNR+qlW63nuACplI5rqp5ZSqS9XonbO3xw7e9HIsIQTkom7srxSrOIuv7kU=@vger.kernel.org X-Gm-Message-State: APuU4Z+NNlSGJ9OwSSYymM1pNS9qA+GcO5OFGYOMtTYDnEuMdYZApHNp fr6gA7GHDrlLTWbxuGzqNfx9NXZKCVGQu/mAaH2lk35QD4F/pZevXfZ1 X-Gm-Gg: AYBFou3D7WLx95l9LxF5TY4ITXzidYPUoxFF6uGNuexQSm9RwKhH1aygReFjoOdERBB JMgYuvkivmRDNhb29++YG8vTqV11qY5XHrntX/y9E6r9rgV3UodEb1QNrcuOA8xhGdYX0t4HfkM Nrh59JznieMYqlXw7uROxDODvIzbI3S0URxYow426vo63HnvolIN38UHL7FpN8CtaufwigHtgFX 6Cn/YFv3iUNKMdwU2bG0AuWKRP+Sc/46IhOCEHDm1nnoxKE4WD83QUZOTVFyUGVpdvB6lIuBdd/ ggYa6S8zACru6B5Tuz/8WcbVRdkDgBQP89IC2GPXXSKufyYfZv46nsRIHrUHUur6VgrdsaCWq0I 8RLuLJpV4xP5ZmRDg8o9rIraiBBuW9FNU8Zx/Mv4NvPpfQRqJvt8n2HpWswc0wlK10atrKafL7l F7evjUByHatU3D9tZnU/0hW8EL1DNm2c6PCaeNU/rf3auPagLTJCJh5KlsTEtndKt/9l3yAFnk8 YyB1OTE0LcMzKGNKuFKQCm8MpTE/5PO3ui54IdQZcrP3v4tXLk8owRbeEIMZkK6/HFdNZyf5gqC PAbVH5Ehjgk2/bTIFLnT0eEtBTIcjbbcv9NiTeaD+Iukdv9zLNdww9qFZEJbUIuGXPyHBxVhswe LBJusCKnBSdk+HoHaODLtD5Zmz6cZvARfpvvfnFgaO8zw0Mk= X-Received: by 2002:a17:90b:3a0e:b0:3b1:4018:bfdd with SMTP id 98e67ed59e1d1-3b182e107dcmr3923372a91.7.1794458146396; Wed, 11 Nov 2026 20:35:46 -0800 (PST) Received: from localhost.localdomain ([183.96.175.225]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3b197c8b287sm2470466a91.15.2026.11.11.20.35.43 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Wed, 11 Nov 2026 20:35:45 -0800 (PST) From: Joonho Lee To: linux-sound@vger.kernel.org Cc: tiwai@suse.com, perex@perex.cz, anton.yakovlev@opensynergy.com, mst@redhat.com, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, corbet@lwn.net, skhan@linuxfoundation.org, rdunlap@infradead.org, linux-doc@vger.kernel.org, Joonho Lee Subject: [PATCH v28 07/17] ALSA: virtio: Recover PCM state after a failed start Date: Thu, 12 Nov 2026 13:35:06 +0900 Message-ID: <20261112043516.37010-8-mynameisjune111@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261112043516.37010-1-mynameisjune111@gmail.com> References: <20261112043516.37010-1-mynameisjune111@gmail.com> X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Capture trigger queues I/O messages before PCM_START. If the START message cannot be allocated or sent, transfers may remain queued, and ALSA does not invoke the action undo callback for the failed trigger. Mark the stream stopped and disable transfers for every failed START path. Arm runtime->stop_operating so sync_stop releases pending I/O and prevents prepare, hw_params, or START retries until release succeeds. Latch a transfer XRUN in both playback and capture, and schedule the existing period worker so a running or draining core stream sees the pointer error. This also retires a failed playback START during drain, where drain-init can already have advanced the core state to DRAINING. The stopped flag is shared with ACK callbacks that can run without the ALSA stream lock. Protect every stopped access with vss->lock. Read the pending message count under the same lock in open and hw_params. In sync_stop, decide whether RELEASE is needed and mark the stream stopped in one locked transition; leave it stopped when release or draining fails. Always cancel elapsed-period work in sync_stop, even when no RELEASE is needed. Record the RELEASE obligation after successful PREPARE and clear it as soon as RELEASE succeeds. If the subsequent RX wait fails, retry that wait without submitting RELEASE again. Fixes: da76e9f3e43a ("ALSA: virtio: PCM substream operators") Assisted-by: LLM Signed-off-by: Joonho Lee --- sound/virtio/virtio_pcm.h | 6 +- sound/virtio/virtio_pcm_ops.c | 113 +++++++++++++++++++++++++++++++---------- 2 files changed, 89 insertions(+), 30 deletions(-) diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h --- a/sound/virtio/virtio_pcm.h +++ b/sound/virtio/virtio_pcm.h @@ -26,13 +26,13 @@ * @hw: Kernel ALSA substream hardware descriptor. * @elapsed_period: Kernel work to handle the elapsed period state. * @lock: Spinlock that protects fields shared by interrupt handlers and - * substream operators. + * substream operators, including @stopped. * @buffer_bytes: Current buffer size in bytes. * @hw_ptr: Substream hardware pointer value in bytes [0 ... buffer_bytes). * @xfer_enabled: Data transfer state (0 - off, 1 - on). * @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun). * @stopped: True if the substream is stopped and must be released on the device - * side. + * side; protected by @lock. * @prepared: True after device PREPARE and the core pointer reset succeed; * protected by @lock. * @preparing: ACK gate through teardown and prepare's core reset; @@ -62,6 +62,8 @@ bool stopped; bool prepared; bool preparing; + /* Successful PREPARE still needs RELEASE; protected by lock. */ + bool release_required; bool suspended; struct virtio_pcm_msg **msgs; unsigned int nmsgs; diff --git a/sound/virtio/virtio_pcm_ops.c b/sound/virtio/virtio_pcm_ops.c --- a/sound/virtio/virtio_pcm_ops.c +++ b/sound/virtio/virtio_pcm_ops.c @@ -116,6 +116,17 @@ } } +static void virtsnd_pcm_start_failed(struct virtio_pcm_substream *vss) +{ + scoped_guard(spinlock_irqsave, &vss->lock) { + vss->xfer_enabled = false; + vss->stopped = true; + vss->xfer_xrun = true; + } + vss->substream->runtime->stop_operating = true; + schedule_work(&vss->elapsed_period); +} + /* Keep completed RX data valid while RELEASE drains the device queue. */ static void virtsnd_pcm_block_ack(struct snd_pcm_substream *substream) { @@ -148,7 +159,7 @@ SNDRV_PCM_HW_PARAM_PERIODS); scoped_guard(spinlock_irqsave, &vss->lock) - vss->stopped = !!vss->msg_count; + vss->stopped |= !!vss->msg_count; vss->suspended = false; /* @@ -250,13 +261,26 @@ { struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); struct virtio_device *vdev = vss->snd->vdev; + unsigned int msg_count; + bool stopped; int rc; virtsnd_pcm_close_ack(substream, false); - if (virtsnd_pcm_msg_pending_num(vss)) { + scoped_guard(spinlock_irqsave, &vss->lock) { + msg_count = vss->msg_count; + stopped = vss->stopped; + } + if (msg_count) { dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n", vss->sid); + return -EBADFD; + } + if (stopped) { + dev_err(&vdev->dev, "SID %u: stream release failed\n", + vss->sid); + scoped_guard(pcm_stream_lock_irqsave, substream) + substream->runtime->stop_operating = true; return -EBADFD; } @@ -310,7 +334,18 @@ struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); struct virtio_device *vdev = vss->snd->vdev; struct virtio_snd_msg *msg; + bool stopped; int rc; + + scoped_guard(spinlock_irqsave, &vss->lock) + stopped = vss->stopped; + if (stopped) { + dev_err(&vdev->dev, "SID %u: stream release failed\n", + vss->sid); + scoped_guard(pcm_stream_lock_irqsave, substream) + substream->runtime->stop_operating = true; + return -EBADFD; + } if (!vss->suspended) { if (virtsnd_pcm_msg_pending_num(vss)) { @@ -353,6 +388,7 @@ scoped_guard(spinlock_irqsave, &vss->lock) { vss->xfer_xrun = false; + vss->release_required = true; } return 0; } @@ -402,33 +438,40 @@ guard(spinlock)(&vss->lock); if (vss->preparing || !vss->prepared) return -EBADFD; + if (vss->stopped) { + substream->runtime->stop_operating = true; + return -EBADFD; + } if (vss->direction == SNDRV_PCM_STREAM_CAPTURE) rc = virtsnd_pcm_msg_send(vss, 0, vss->buffer_bytes); - if (rc) - return rc; - vss->xfer_enabled = true; + if (!rc) + vss->xfer_enabled = true; + } + if (rc) { + virtsnd_pcm_start_failed(vss); + return rc; } msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_START, GFP_KERNEL); if (!msg) { - guard(spinlock_irqsave)(&vss->lock); - vss->xfer_enabled = false; - + virtsnd_pcm_start_failed(vss); return -ENOMEM; } - return virtsnd_ctl_msg_send_sync(snd, msg); + rc = virtsnd_ctl_msg_send_sync(snd, msg); + if (rc) + virtsnd_pcm_start_failed(vss); + + return rc; case SNDRV_PCM_TRIGGER_SUSPEND: - scoped_guard(spinlock_irqsave, &vss->lock) - vss->suspended = true; + vss->suspended = true; fallthrough; case SNDRV_PCM_TRIGGER_STOP: - scoped_guard(spinlock_irqsave, &vss->lock) - vss->stopped = true; - fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_PUSH: scoped_guard(spinlock_irqsave, &vss->lock) { + if (command != SNDRV_PCM_TRIGGER_PAUSE_PUSH) + vss->stopped = true; vss->xfer_enabled = false; } @@ -459,26 +502,38 @@ struct virtio_snd *snd = vss->snd; struct virtio_snd_msg *msg; unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms); - bool stopped; + bool need_release; int rc; virtsnd_pcm_block_ack(substream); + scoped_guard(spinlock_irqsave, &vss->lock) { + vss->xfer_enabled = false; + need_release = vss->release_required; + if (need_release) + vss->stopped = true; + } cancel_work_sync(&vss->elapsed_period); - scoped_guard(spinlock_irqsave, &vss->lock) - stopped = vss->stopped; - if (!stopped) - return 0; - - msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE, - GFP_KERNEL); - if (!msg) - return -ENOMEM; - - rc = virtsnd_ctl_msg_send_sync(snd, msg); - if (rc) - return rc; + if (need_release) { + msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE, + GFP_KERNEL); + if (!msg) { + scoped_guard(pcm_stream_lock_irqsave, substream) + substream->runtime->stop_operating = true; + return -ENOMEM; + } + + rc = virtsnd_ctl_msg_send_sync(snd, msg); + if (rc) { + scoped_guard(pcm_stream_lock_irqsave, substream) + substream->runtime->stop_operating = true; + return rc; + } + + scoped_guard(spinlock_irqsave, &vss->lock) + vss->release_required = false; + } /* * The spec states that upon receipt of the RELEASE command "the device @@ -492,6 +547,8 @@ if (rc <= 0) { dev_warn(&snd->vdev->dev, "SID %u: failed to flush I/O queue\n", vss->sid); + scoped_guard(pcm_stream_lock_irqsave, substream) + substream->runtime->stop_operating = true; return !rc ? -ETIMEDOUT : rc; }