From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.216.53 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794458147; b=ANw0oKd4A6I0XR3HO50sjWRmNFYaKbWRN6XNRJETUXqKywTO3gT/OGCsx+Bory/06R93 ES+F00wjXsdoPkC/rsHfg49k6YX8yBSY+VcgiLAp1BCTw1BskOU/ei5YHgv+I0SZF3SoB LRzVAPTITi4JLpN85ZDZhZOF/9oOuzvaHiSYfdbTdX8m3V9U4zzFT6ZZ6eMVJDAnXRrdc bv3YbxItRFM5wweayQUyMpZpf5DyELfgW18BLNC8jlree3CZRBbRUUEWWmiC40PquKciM Y1tjMWLNfIgSpqMjR8gz0Yo44qeMLIkquagiGbaEYq3xNe25T6OQG/muiFd2OF8heLw== 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=wPdSwOtZbqcSHNDaZ7KNzx/avCLMnlKFxdDPRs9h5oRUbg7sHUy8YsEAPT0QwWgc0rax e1Xn5nGdu/XtFY5zG1m+F4gEDApa+oyxJdIicuPSIZPxGaTFG2h6Oxpl/iyWB1b1McJV5 X7O9+lEBTdo51RAVCCew+bwEzfRzW0pKkXX9y0LhTCFUAPexl8go17WAYsc2yKzk5xTF2 s5kboKD+bJNzhDj/4h+BhIXWI4l7Y8AMhFmKDEtVakSfyk3H6dfoOtmuYAcSD1AaJf2rb kiazfHCY6Z3RiEn86dDpyUKOyGdkyQnLW8f0/0QeOc0A+lZr8Dd9hC6IFcA+scIKNhg== 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=209.85.216.53 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) (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 10C8F60A380E for ; Thu, 12 Nov 2026 04:35:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 10C8F60A380E 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-pj1-f53.google.com with SMTP id 98e67ed59e1d1-3b179528d56so969510a91.3 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=Ccw6PftHkgs+DQMHmmLljAQvDn0Uh0ePe6ZBSytoDjaa9RLE2aEG2ZaZfrqV8con6z 5gcM00RcE9LwN75+///3fXT1diAzKVDQU100A5QjDYu/b04XKX1dNmbkRsINS2WbbS7+ P2qfuHaacDWw6LYct1lDoTz3O2eFq3nA5ppWBEO8d3tFOYkWOEwy46n4IzgT6sk85LII qYunPNncoxSxdaFcJOAMFeusH/LAoq2V6O/7PKpnHDIhxjZbGHLoIgMotHJU0BV7NdA3 JQdLUxTTsaZkNQ27Ujv1IaHij0SuTK5a3nHS0W3x4Bcc/rZKuE9BvWc9w4D5IAT5gCP3 PEKQ== X-Forwarded-Encrypted: i=1; AL+hErE56zzCieAOIfAtLl/uLpSx5U3uveInACQ+IGJddK7+I01mPI3TJyxI9g2hrhbquahuNAHiflkPm4R/P8w=@vger.kernel.org X-Gm-Message-State: APuU4Z8xphF8bGT0EQ/9SXfAUZnMGE4gdL9rd2d1BUEC6E6bZIB9DqVn T08AOGKPCTvgSStNeFldc9kFNKXpn+ua800EEbvJN8DtlUTO0b/I5y7j X-Gm-Gg: AYBFou3bCDAgQYRILAKpkkP9YYLECIL4svD7P//PC27DgpJACxNtNiN5K7pXjPisu2C qfiwCGWAncx1E92whr1AdnjX/UX2b3lL5KA+n8Jxht44LiHAeCV4XVw63fEYcv80kaww46Hf8tu bAxDRNAF9t1AJ8pnhiFTSIfzsJ+VmnybsUADnVsUsLIZDYImol5u+rz6TG86+L8f3aulI/XddlK Cj9SU2WAQJWsvLZg2FjiD8L6mU0UQucbfJBF1dvURx2bsW4rGYvo6vDoHIia7SrZFtyq8QgeJ7+ Snkx6mLGrWYA0SGkVVVYDLcQlwrZar/LeUQt61sKwHPmLoOOtJFV81xlhDgF02UCXRyk3dYDoyV pxooqr+CjQbAxO4moB8gufhd/P0S3GfaJ354EcA/KL1dnw3GJOyVK2b0o8HfkOQq3J1VJiT6ahI 5txjbHM+9BTMQiILzmQaFd8tzTqQtxnJw59OwLRbfL+vdSyvC56cxLfwu0P68LgZX/pwjR7gi6e bfi2gpZO87DWf4uEQJJf7ovbD5f1uEZuQQBB2vxgs5DQ5l3ffU2fCRZXKJaF5pmNXEOIZr0UzBw cpaK9GS0lI4q39pvuzxIeOyan+omx0Lo/XJ9M0NOr8nbfbMkD/O8jUjLT0/IjlTQgwIki1YEPOY 1Av0xdzTcdCF+XiEovxksXqYpIKLg5Gcy8s30fzgr/SSoOAo= 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-kernel@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; }