From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.216.52 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793180507; b=3643XHDy1+isOjtxvMCvrSygNtWaR2bOr0ciDLplEb6U1qtsr8E2wlZaMhLRNH7LviQf jxyVMoRAEi7e7eUbgWBS77jizyyjPRmrzwILgT34tQ2znlh99o4FRJBwt0kfcYFXGzzhU v621E7fSPLOHKd8z3dLwO8lBD0wmSp3b9Wq4oK4zJcRL0UgZiHAPbTnlcM9gIWTeK11Ub B7yESEkbvlRocGqvDFYiW1SGCAW3u7WAJ8k06qdNYJa0eaK+w7rdUvePL4UKdXL5ywWPN K8W8T2am/NCOzsJ2aG8es7+F0c2QBc+HBe/Ux63FzCP1bHUpDnJjv8Hx7kmhYO1JgUQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793180507; 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=cwJJNaSJlKm/koK5kjoFQnQ8cfxssNfTJLq5LnG8GkA=; b=oy2lJti4zkYWeIv0zqmeOebs+M4ErK4vTp1ncHkcPjgmLyyPcGX4yddikH1PCzFi2lyk lL3iRMmFPy3DlVXjWNtcrYAach0/3HChGiU3UG8gNIk24UbDGT6iNNJyxNVaO0s8mvx1v qht0Z45oevFcMb8FlhED61S5pe42NwIRuXsrh5nstLwBXt2CatAWP6Tzd5noU25wLv1H5 Z87fUHu47G8lpwAvScZk2Z4+kDAZ1Qb2h6uXgVGk/B1j5w7ZsyVfXAuPuYRRhF7CLBOaO Tb4QyKKwfk2R4wa4hfmIcynkV+Mm8n6aQR1xqT3P3LP41Hqv5Fboz02M/I+0nU0J6lw== 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=vm1XrEKV; arc=none smtp.remote-ip=209.85.216.52 Received: from mail-pj1-f52.google.com (mail-pj1-f52.google.com [209.85.216.52]) (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 6CED8606A32A for ; Wed, 28 Oct 2026 09:41:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6CED8606A32A 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=vm1XrEKV Received: by mail-pj1-f52.google.com with SMTP id 98e67ed59e1d1-3ae486f8a27so524684a91.0 for ; Wed, 28 Oct 2026 02:41:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1793180507; x=1793785307; 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=cwJJNaSJlKm/koK5kjoFQnQ8cfxssNfTJLq5LnG8GkA=; b=vm1XrEKVLlyO+ACYvXChwxf3UsS10+MpmZims/56Ff7NTOpWBuZzk5mZzNtyRJNq5a ilLmgDeRrJVGyHpHZuVThRThWKkSF+vBRT4usYJ2dviQV+SLA/Rach2rIxYNKh/glKo0 Nvwnc9ms6TCgfUvRm1SkeD9KJ+K6iT0VW56Kj5P0CxJfudZiJ1hsuyAFrD8x4W7i8tB9 IQEWdK5d4EYgN5jlQIvdU1ijtoUOx0z4G0imO2AOtiO84s1+/nCPMKD3XJNT4jaqAR4g xvQW7hwE1dp5AkfvX/1mA95Shz4nKKmpgqQP6V7eRtIuqD4YxRcIt+RUGCXEqofsbeeL RT8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793180507; x=1793785307; 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=cwJJNaSJlKm/koK5kjoFQnQ8cfxssNfTJLq5LnG8GkA=; b=hxropvNAYJBQAtjXKKUFSSUFOHgj7Z8K/EhLmHrm21OwIrgKE3e8+ilGHtyfpA+Fxa 5pCJM8DA5+OvZ7zPZOqAZ6dGNGfUNX4UoJtC6VwT3hkGmB1WsQPNc+aFE3wBdQ2xOCeV L8AWTeXNBH3j0qnT3S1JG/v5UUvG0igYUO21GW8K5h6xazdkg+0YN81qegp+tiiDrO2M iinEnJGnytpg0vUfZ7/LxaSl7R2qBXEeG98TYCqRX08F4IYI7mi4BK1WWMDmcoTr07kE WSs1NGmj8QlGhVvVPMI5DU4aKw+y3ktrq2pHH73XsYR1OKz8MRrb/yllyZkyVNub5S8W 5f0Q== X-Forwarded-Encrypted: i=1; AKwUvBzPGJn0lc8Vx89nyYfNGyaftrt1iWGuyDABfrPPVz0cMKC1X+GCi/gnwfilqJzHbDiUKbkI7IUkiYA=@vger.kernel.org X-Gm-Message-State: AFq9FYK6PEcExyUhK6p8YQ+hHrUn8JtcLsM68wNdMT9ryRw02h1SlQ51 eecVx5qDvZ42vicB+BfHPJsdtGLh5RmVkSlQfBw0xtEO4O3vEdHCsZPX X-Gm-Gg: AYBFou1WGaJs007BBgk/ue8mIgefX/eK0hR+VXIMdicsgbHvDCs7ABX5Z8y9RZL+r9+ 5NPp76sI5T7Q/+Lw8Q52GZVIPMmYaxu9Qw/bF8uQC1tByJ3AEOeEKXS4RYUQB3rGMhaLm/nyxx1 ESi2MIjIE5cEpwAbBMz07XLPeNdOeqch1lCYzKUIiu4lroTtpXZOtc9dq7xaT4LGqlJv72MA2Rv Uz7+Jw03vdOUEmGbtFZ8n6+trdrfVYZK/9NYTdjU9mxrpMcGoCh7AJxaQNg+rvjQnoBp3vV2Y6B 72+NjEt/PoJpqhMVyCZPhHmX+WomnG8+NC9cTGNVHn77/ua0kKkPAtdSzegsWiedUFQXlcP1PHy grbEZ/Zsi+h7UwOGaF/QYU+TXh4eHO+QiQS8B1ij5CVKN8RPgz3Kl8RIKmy90va3sow3gb1gvqL RPKdL2kc7Ty83Sbtu23Xv66zFzXzjf8aCkv0HTG4svhCJ8j4E085WUjp01m1/2eleTgOnSLXUxi txowLegzbm+//HcjmsL9wnFhdt/m335fcjfJIzWWTjh0bMwSiG6oegUaHBC2Xj11oGIPKvyPH3Q lMEx6qB0O4bVraMpHrXSVJ0O61T+sKy+qGWL1yDXjKm1WZPTp4iIXD1e+/rzQYJm0fskVDZtP8n oPPnWnkk2OcnTu/2DrnpTY28jNwgKT5Q4vTXNvYpGSCgbyRk= X-Received: by 2002:a17:90b:264d:b0:3aa:f4af:1e0f with SMTP id 98e67ed59e1d1-3ae57e07351mr1289738a91.8.1793180506752; Wed, 28 Oct 2026 02:41:46 -0700 (PDT) Received: from localhost.localdomain ([183.96.175.225]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3ae5a93b3f5sm2242377a91.5.2026.10.28.02.41.43 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Wed, 28 Oct 2026 02:41:46 -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 v7 02/16] ALSA: virtio: Recover PCM state after a failed start Date: Wed, 28 Oct 2026 18:41:18 +0900 Message-ID: <20261028094132.20364-3-mynameisjune111@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261028094132.20364-1-mynameisjune111@gmail.com> References: <20261028094132.20364-1-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. Fixes: da76e9f3e43a ("ALSA: virtio: PCM substream operators") Assisted-by: LLM Signed-off-by: Joonho Lee --- Changes in v3: - Protect all stopped accesses with vss->lock. Keep the RELEASE decision and stopped transition in the same critical section. sound/virtio/virtio_pcm.h | 4 +- sound/virtio/virtio_pcm_ops.c | 81 +++++++++++++++++++++++++++++------ 2 files changed, 69 insertions(+), 16 deletions(-) diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h index 8837dfc12828..8048b14e6c80 100644 --- a/sound/virtio/virtio_pcm.h +++ b/sound/virtio/virtio_pcm.h @@ -26,13 +26,13 @@ struct virtio_pcm_msg; * @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. diff --git a/sound/virtio/virtio_pcm_ops.c b/sound/virtio/virtio_pcm_ops.c index a40ea394bf17..970499fe419b 100644 --- a/sound/virtio/virtio_pcm_ops.c +++ b/sound/virtio/virtio_pcm_ops.c @@ -96,6 +96,15 @@ static const struct virtsnd_a2v_rate g_a2v_rate_map[] = { 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 @@ static int virtsnd_pcm_open(struct snd_pcm_substream *substream) 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; /* @@ -217,13 +227,25 @@ static int virtsnd_pcm_hw_params(struct snd_pcm_substream *substream, { 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; + } rc = virtsnd_pcm_dev_set_params(vss, params_buffer_bytes(hw_params), params_period_bytes(hw_params), @@ -273,6 +295,16 @@ static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream) struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); struct virtio_device *vdev = vss->snd->vdev; struct virtio_snd_msg *msg; + bool stopped; + + 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)) { @@ -338,31 +370,40 @@ static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command) 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 +434,31 @@ static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream) 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->stopped || vss->msg_count; + if (need_release) + vss->stopped = true; + } cancel_work_sync(&vss->elapsed_period); - - if (!vss->stopped) + if (!need_release) return 0; msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE, GFP_KERNEL); - if (!msg) + if (!msg) { + substream->runtime->stop_operating = true; return -ENOMEM; + } rc = virtsnd_ctl_msg_send_sync(snd, msg); - if (rc) + if (rc) { + substream->runtime->stop_operating = true; return rc; + } /* * The spec states that upon receipt of the RELEASE command "the device @@ -421,11 +472,13 @@ static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream) 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; } -- 2.54.0 (Apple Git-157)