From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.174 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793412547; b=xE8WQmPxwkEn0AtLhbj9VGh4m5yenBd9sBbzIRb+lhOdYfasYbCH6gcOs/nzVyjSm0cB vZTR8BjOnk49+UIj2DuakAOpjNz0cKnQwEIGCxbCDsAac6cZUrXESDC+GBYX0jH0D7Q4Q lCCf/JEtNReJ3Y3ZO+Fe+iGh1oCAAommFIrqtNKMpYv5MdN2XKm4hifcPCZpbfaTF5siK t/HpCSseUc1ma2C7j4Qyk964Ptl8rOtyKDKsE74XyO55mm21V/rmPAKlGdVQWkwuezoO/ e5kGj05XLesNqQsrDWyTiLYk2ipdP0cHt2BO2nOHDY3f/+CmI/rNu4kAYeiwQQ/lOMw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793412547; 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=pPsijI/WFroQ3WU8JWBkdFg+dO3cPuO9jwy6Y07G2CQ=; b=m6Q+he8owdoZbUaUUaD7Dle33p8WRxNzEaS5KYOfP8aA3pZVVs3PvwefNFh/VmBasz+Y DTRvCotzfPwG9I6uyd3XGwMLpt65F7gkwdPL7UXfcpj53++nKsZez6Tk8lqYlygw19II9 teu2pHuO6GXFzoRnyseUFn2/kHBgu34XACV/WFu2LnUtPgWfnx/YjweIwKLRNiVi6Khma eUgg8XYx2FHlTJRAfFRP3znHu076uDyuMFnt/7wypSNGIlJJJGVqgfXftiwwTTS/cN1fL lVSwgrv+YvAUjt1PINWoY2Tw1ldkyqeBc453yX5u5NmoVLpUEjfl0wSvQUYS+obpaIg== 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=si3PVKTy; arc=none smtp.remote-ip=74.125.82.174 Received: from mail-dy1-f174.google.com (mail-dy1-f174.google.com [74.125.82.174]) (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 1A746606A33B for ; Sat, 31 Oct 2026 02:09:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 1A746606A33B 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, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=si3PVKTy Received: by mail-dy1-f174.google.com with SMTP id 5a478bee46e88-33bf40b0c8bso751689eec.0 for ; Fri, 30 Oct 2026 19:09:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1793412546; x=1794017346; 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=pPsijI/WFroQ3WU8JWBkdFg+dO3cPuO9jwy6Y07G2CQ=; b=si3PVKTyQ2BO+TPbxT2fFaK4Vo3+xbQq4y/3vBnM977TD3eUh6ZGepMtfQlyNCiyZa j4+2DaIdNTgTsv/33jVuSE5fuwo2EALss74/yb42NJizhkCViR4KdYR26670pdao6XHx iErsUAPp3d1Jsdgz7dGWmHdZppqj33Tg8mL9qfZ9IY2OitMXRwEeqmst+JaQO3KHOivW GnOaj1QaTa1LyZTCTxmR/2586oBYbXS/JiYAQwutQUZFIeHVLnY115VWreMSF+4Mss7s kRMBBUIUM5/xZJLBvUpxJEui1V7yR9ehTNIgtf9LY5cVtzjYP16jBcuGyZX6dg+SEODP D0FQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793412546; x=1794017346; 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=pPsijI/WFroQ3WU8JWBkdFg+dO3cPuO9jwy6Y07G2CQ=; b=PgdnVl+FtXewYOoKHUVg3xQVdrL0NePKjBlAUtfWSzIcGeehGd/QsOHfrJs5n3o1X0 7UO/CEUBggl1nxEKsbgIcov7SlxRQhGzWVBaPXqvwRL2plFRV/KnlMbwb49Zy28kYxL7 7/NLhNGXAtTXQSDqJbjC9P69oTVfSLnwziCUzLpDxOD1G00pKY6SkGNZI6bUNsZ3vrjA vnfmq9JMx1fWOtYBEqwSthvcl+D7OXDACoxOn3d93N2f4axvvMiUCTHjvEaVzRGWsB/0 c1rqFOYdve+68dr8Tvf7wCNUKz1MbjmbAGqvlvL0SOQc7Wv1945uz9Sn5OqIr05AH3YF FQ0A== X-Forwarded-Encrypted: i=1; AKwUvBx2A8uQ8nysSbWCyYhNRpX2UIS2ig7oS4VOG+0jjEFuTq2uXmeCPWOHwmNllr/hyix00o+vnrwB0yQ=@vger.kernel.org X-Gm-Message-State: AFq9FYLU1Gup1TjPvrHiGiPfFi0NG2B7Vjk7UKyAX6yyCGA864tbVZY2 HZt8NULkXm6b314RSZaTlDobm/vvrerQcszQ50Q+BeEDDyd6MDZvUKKG X-Gm-Gg: AYBFou3G0XTCVhrYDDcKW6zx8WD3aEtF65w5xFrVC/0ZN3+J07LY8X+vTPOJ9ONPEAV nyycUrdYmMNM7+mHZBHlSpOgA6JT2O0I8ol/73RNRkpRM04Zbbm6v57q6VDAAfxFX+KlSQTEBD5 GnEO7SEwNd3/RjoeYpoh+89lKfR0WjbEiu+8nHmcuYW8bf+VhZSkwNzeKVIUewsHkXli6qVxcxh UGIFipDxaeCeYNGyiLNjBG1EvYlBjBidCriSVx6sPpnBaIew1Vzg5DD9hNTDGp1VH9OD2B8rCPI T3Cu7f8n/TexoRadHE8W6WB+LVClOVu4vNqRPz/f0etoac/K00qCX03YzIB81cm1gvx7v/+EZ8+ 9F8FJJLk0qtWaGX4xMiZaVDCNa1f+buiqcnWxP/FUTzyosQ6eFIQkaAVQpaCCBYa3yTMaiA3IBL /HuFmP9y0ut1Abm8EgnCoiGCwFPcz9OYg00I4Xy/r6qm20v+TkjFu9iM1o3zDv65CoFYIuP/aOK sICc7s9RZqy3hWOxCPxzo5w0/ouI3xdACzf45CgyLfG4w9YKcmnUnq+I3RPBquu1giUGOxm3K4g 3VuVz185mKLGugQds+XYkXSa7mtoBRp0wvPX/08oUcp/bfbslZ+gmA/vm7yeH20JtSsiRNGo3ad JN/rQRlx42Mv7UKg7JJcleU8IG6WCGwJonCGhtPTLnOf4PA== X-Received: by 2002:a05:693c:83cf:10b0:36a:1427:3933 with SMTP id 5a478bee46e88-36a4236e7bemr6531801eec.16.1793412546048; Fri, 30 Oct 2026 19:09:06 -0700 (PDT) Received: from localhost.localdomain ([180.182.24.11]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-36a42a77c0dsm13214096eec.26.2026.10.30.19.09.03 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Fri, 30 Oct 2026 19:09:05 -0700 (PDT) From: Joonho Lee To: linux-sound@vger.kernel.org Cc: tiwai@suse.de, 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 v11 02/14] ALSA: virtio: Recover PCM state after a failed start Date: Sat, 31 Oct 2026 11:08:43 +0900 Message-ID: <20261031020855.2402-3-mynameisjune111@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261031020855.2402-1-mynameisjune111@gmail.com> References: <20261031020855.2402-1-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. 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 --- 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. * @suspended: True if the substream is suspended and must be reconfigured on * the device side at resume. * @msgs: Allocated I/O messages. @@ -56,6 +56,8 @@ bool xfer_enabled; bool xfer_xrun; bool stopped; + /* 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 @@ -96,6 +96,15 @@ static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream); +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->substream->runtime->stop_operating = true; +} + /** * virtsnd_pcm_open() - Open the PCM substream. * @substream: Kernel ALSA substream. @@ -115,7 +124,8 @@ snd_pcm_hw_constraint_integer(substream->runtime, SNDRV_PCM_HW_PARAM_PERIODS); - vss->stopped = !!virtsnd_pcm_msg_pending_num(vss); + scoped_guard(spinlock_irqsave, &vss->lock) + vss->stopped |= !!vss->msg_count; vss->suspended = false; /* @@ -217,11 +227,23 @@ { 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; - 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); + substream->runtime->stop_operating = true; return -EBADFD; } @@ -273,6 +295,17 @@ 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); + substream->runtime->stop_operating = true; + return -EBADFD; + } if (!vss->suspended) { if (virtsnd_pcm_msg_pending_num(vss)) { @@ -311,7 +344,12 @@ if (!msg) return -ENOMEM; - return virtsnd_ctl_msg_send_sync(vss->snd, msg); + rc = virtsnd_ctl_msg_send_sync(vss->snd, msg); + if (!rc) { + guard(spinlock_irqsave)(&vss->lock); + vss->release_required = true; + } + return rc; } /** @@ -338,31 +376,40 @@ scoped_guard(spinlock_irqsave, &queue->lock) { guard(spinlock)(&vss->lock); + 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) + if (rc) { + vss->stopped = true; + substream->runtime->stop_operating = true; return rc; + } vss->xfer_enabled = true; } 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: vss->suspended = true; fallthrough; case SNDRV_PCM_TRIGGER_STOP: - 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; } @@ -393,21 +440,34 @@ struct virtio_snd *snd = vss->snd; struct virtio_snd_msg *msg; unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms); + bool need_release; int rc; + 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); - if (!vss->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) { + substream->runtime->stop_operating = true; + return -ENOMEM; + } + + rc = virtsnd_ctl_msg_send_sync(snd, msg); + if (rc) { + 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 @@ -421,11 +481,13 @@ if (rc <= 0) { dev_warn(&snd->vdev->dev, "SID %u: failed to flush I/O queue\n", vss->sid); + substream->runtime->stop_operating = true; return !rc ? -ETIMEDOUT : rc; } - vss->stopped = false; + scoped_guard(spinlock_irqsave, &vss->lock) + vss->stopped = false; return 0; }