From patchwork Mon Jan 23 17:25:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Fitzgerald X-Patchwork-Id: 648058 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8688BC54EAA for ; Mon, 23 Jan 2023 17:26:21 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 883521FA; Mon, 23 Jan 2023 18:25:29 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 883521FA DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1674494779; bh=qfUudCFzb8HxWifwe9JCu4GEdzd8XI6XBh77W9eooms=; h=From:To:Subject:Date:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:Cc:From; b=hCcTjaeL8C6b1izS2c4uJMZpGZXUKJfU0dnhDFFYB+AMSPJcaAe5MQZMM2PHG9cRs 65HWDNoR+WU9ZS16ykGubXTGc2qGP+EuzPO3vq/YL4GZBMd0x8Y41q3exUe7Wk/G1g G0g51Q1hpZk1cN+nmYwBop1vdnRN5Sc/iAkYiwig= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 04FA0F801D5; Mon, 23 Jan 2023 18:25:29 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 1E152F804A9; Mon, 23 Jan 2023 18:25:28 +0100 (CET) Received: from mx0b-001ae601.pphosted.com (mx0b-001ae601.pphosted.com [67.231.152.168]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id B92BCF800FB for ; Mon, 23 Jan 2023 18:25:24 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz B92BCF800FB Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key, unprotected) header.d=cirrus.com header.i=@cirrus.com header.a=rsa-sha256 header.s=PODMain02222019 header.b=YIZBgrKs Received: from pps.filterd (m0077474.ppops.net [127.0.0.1]) by mx0b-001ae601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30N9hVtL020791; Mon, 23 Jan 2023 11:25:22 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cirrus.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=PODMain02222019; bh=NpDgslDK1ayNWniug1IvgLrf8tEcC4MbeDjEHxsnddw=; b=YIZBgrKsH+zjG8PumM3rytDEG/VF/UIn33u3VrrXUHRCBdHueVWvxDq7vtcmQRQwUn60 aic37TbVt/j4kbHp+1Kn0gVunLlSqzih2Lt4wcVvEWNZd7smkKP+Md1sPjjPMn8/I8B9 HTZb8UOH7bG0QNhnobIzncKGLKDQZ8RoWM1Dkrkg1XN9VABSsZBzWU9Yxx2aeHSJCldR 6EVZ5yXVshO+Q+B2RNZme2CzQEFDHy8ZWaL1MvXqJ4nJ6QvieSR2rm5yKXVn3r8z7PcG axBWMOUXYp5gQh/Q453KTZ5TIqWHgG7Wzr9DRPcWy4qsW28Kdb0Jk/PmXdJ+atsp1eQR qQ== Received: from ediex02.ad.cirrus.com ([84.19.233.68]) by mx0b-001ae601.pphosted.com (PPS) with ESMTPS id 3n8dbskqkg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 23 Jan 2023 11:25:22 -0600 Received: from ediex02.ad.cirrus.com (198.61.84.81) by ediex02.ad.cirrus.com (198.61.84.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.21; Mon, 23 Jan 2023 11:25:20 -0600 Received: from ediswmail.ad.cirrus.com (198.61.86.93) by anon-ediex02.ad.cirrus.com (198.61.84.81) with Microsoft SMTP Server id 15.2.1118.7 via Frontend Transport; Mon, 23 Jan 2023 11:25:20 -0600 Received: from edi-sw-dsktp-006.ad.cirrus.com (edi-sw-dsktp-006.ad.cirrus.com [198.90.251.127]) by ediswmail.ad.cirrus.com (Postfix) with ESMTP id E2212B06; Mon, 23 Jan 2023 17:25:20 +0000 (UTC) From: Richard Fitzgerald To: , , , Subject: [PATCH v2] soundwire: bus_type: Avoid lockdep assert in sdw_drv_probe() Date: Mon, 23 Jan 2023 17:25:20 +0000 Message-ID: <20230123172520.339367-1-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: cn94IY4-ERbQUqPSKuBsqyGPgGbunahu X-Proofpoint-GUID: cn94IY4-ERbQUqPSKuBsqyGPgGbunahu X-Proofpoint-Spam-Reason: safe X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: patches@opensource.cirrus.com, alsa-devel@alsa-project.org, Richard Fitzgerald , linux-kernel@vger.kernel.org Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" Don't hold sdw_dev_lock while calling the peripheral driver probe() and remove() callbacks. Holding sdw_dev_lock around the probe() and remove() calls causes a theoretical mutex inversion which lockdep will assert on. During probe() the sdw_dev_lock mutex is taken first and then ASoC/ALSA locks are taken by the probe() implementation. During normal operation ASoC can take its locks and then trigger a runtime resume of the component. The SoundWire resume will then take sdw_dev_lock. This is the reverse order compared to probe(). It's not necessary to hold sdw_dev_lock when calling the probe() and remove(), it is only used to prevent the bus core calling the driver callbacks if there isn't a driver or the driver is removing. All calls to the driver callbacks are guarded by the 'probed' flag. So if sdw_dev_lock is held while setting and clearing the 'probed' flag this is sufficient to guarantee the safety of callback functions. Removing the mutex from around the call to probe() means that it is now possible for a bus event (PING response) to be handled in parallel with the probe(). But sdw_bus_probe() already has handling for this by calling the device update_status() after the probe() has completed. Example lockdep assert: [ 46.098514] ====================================================== [ 46.104736] WARNING: possible circular locking dependency detected [ 46.110961] 6.1.0-rc4-jamerson #1 Tainted: G E [ 46.116842] ------------------------------------------------------ [ 46.123063] mpg123/1130 is trying to acquire lock: [ 46.127883] ffff8b445031fb80 (&slave->sdw_dev_lock){+.+.}-{3:3}, at: sdw_update_slave_status+0x26/0x70 [ 46.137225] but task is already holding lock: [ 46.143074] ffffffffc1455310 (&card->pcm_mutex){+.+.}-{3:3}, at: dpcm_fe_dai_open+0x49/0x830 [ 46.151536] which lock already depends on the new lock.[ 46.159732] the existing dependency chain (in reverse order) is: [ 46.167231] -> #4 (&card->pcm_mutex){+.+.}-{3:3}: [ 46.173428] __mutex_lock+0x94/0x920 [ 46.177542] snd_soc_dpcm_runtime_update+0x2e/0x100 [ 46.182958] snd_soc_dapm_put_enum_double+0x1c2/0x200 [ 46.188548] snd_ctl_elem_write+0x10c/0x1d0 [ 46.193268] snd_ctl_ioctl+0x126/0x850 [ 46.197556] __x64_sys_ioctl+0x87/0xc0 [ 46.201845] do_syscall_64+0x38/0x90 [ 46.205959] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 46.211553] -> #3 (&card->controls_rwsem){++++}-{3:3}: [ 46.218188] down_write+0x2b/0xd0 [ 46.222038] snd_ctl_add_replace+0x39/0xb0 [ 46.226672] snd_soc_add_controls+0x53/0x80 [ 46.231393] soc_probe_component+0x1e4/0x2a0 [ 46.236202] snd_soc_bind_card+0x51a/0xc80 [ 46.240836] devm_snd_soc_register_card+0x43/0x90 [ 46.246079] mc_probe+0x982/0xfe0 [snd_soc_sof_sdw] [ 46.251500] platform_probe+0x3c/0xa0 [ 46.255700] really_probe+0xde/0x390 [ 46.259814] __driver_probe_device+0x78/0x180 [ 46.264710] driver_probe_device+0x1e/0x90 [ 46.269347] __driver_attach+0x9f/0x1f0 [ 46.273721] bus_for_each_dev+0x78/0xc0 [ 46.278098] bus_add_driver+0x1ac/0x200 [ 46.282473] driver_register+0x8f/0xf0 [ 46.286759] do_one_initcall+0x58/0x310 [ 46.291136] do_init_module+0x4c/0x1f0 [ 46.295422] __do_sys_finit_module+0xb4/0x130 [ 46.300321] do_syscall_64+0x38/0x90 [ 46.304434] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 46.310027] -> #2 (&card->mutex){+.+.}-{3:3}: [ 46.315883] __mutex_lock+0x94/0x920 [ 46.320000] snd_soc_bind_card+0x3e/0xc80 [ 46.324551] devm_snd_soc_register_card+0x43/0x90 [ 46.329798] mc_probe+0x982/0xfe0 [snd_soc_sof_sdw] [ 46.335219] platform_probe+0x3c/0xa0 [ 46.339420] really_probe+0xde/0x390 [ 46.343532] __driver_probe_device+0x78/0x180 [ 46.348430] driver_probe_device+0x1e/0x90 [ 46.353065] __driver_attach+0x9f/0x1f0 [ 46.357437] bus_for_each_dev+0x78/0xc0 [ 46.361812] bus_add_driver+0x1ac/0x200 [ 46.366716] driver_register+0x8f/0xf0 [ 46.371528] do_one_initcall+0x58/0x310 [ 46.376424] do_init_module+0x4c/0x1f0 [ 46.381239] __do_sys_finit_module+0xb4/0x130 [ 46.386665] do_syscall_64+0x38/0x90 [ 46.391299] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 46.397416] -> #1 (client_mutex){+.+.}-{3:3}: [ 46.404307] __mutex_lock+0x94/0x920 [ 46.408941] snd_soc_add_component+0x24/0x2c0 [ 46.414345] devm_snd_soc_register_component+0x54/0xa0 [ 46.420522] cs35l56_common_probe+0x280/0x370 [snd_soc_cs35l56] [ 46.427487] cs35l56_sdw_probe+0xf4/0x170 [snd_soc_cs35l56_sdw] [ 46.434442] sdw_drv_probe+0x80/0x1a0 [ 46.439136] really_probe+0xde/0x390 [ 46.443738] __driver_probe_device+0x78/0x180 [ 46.449120] driver_probe_device+0x1e/0x90 [ 46.454247] __driver_attach+0x9f/0x1f0 [ 46.459106] bus_for_each_dev+0x78/0xc0 [ 46.463971] bus_add_driver+0x1ac/0x200 [ 46.468825] driver_register+0x8f/0xf0 [ 46.473592] do_one_initcall+0x58/0x310 [ 46.478441] do_init_module+0x4c/0x1f0 [ 46.483202] __do_sys_finit_module+0xb4/0x130 [ 46.488572] do_syscall_64+0x38/0x90 [ 46.493158] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 46.499229] -> #0 (&slave->sdw_dev_lock){+.+.}-{3:3}: [ 46.506737] __lock_acquire+0x1121/0x1df0 [ 46.511765] lock_acquire+0xd5/0x300 [ 46.516360] __mutex_lock+0x94/0x920 [ 46.520949] sdw_update_slave_status+0x26/0x70 [ 46.526409] sdw_clear_slave_status+0xd8/0xe0 [ 46.531783] intel_resume_runtime+0x139/0x2a0 [ 46.537155] __rpm_callback+0x41/0x120 [ 46.541919] rpm_callback+0x5d/0x70 [ 46.546422] rpm_resume+0x531/0x7e0 [ 46.550920] __pm_runtime_resume+0x4a/0x80 [ 46.556024] snd_soc_pcm_component_pm_runtime_get+0x2f/0xc0 [ 46.562611] __soc_pcm_open+0x62/0x520 [ 46.567375] dpcm_be_dai_startup+0x116/0x210 [ 46.572661] dpcm_fe_dai_open+0xf7/0x830 [ 46.577597] snd_pcm_open_substream+0x54a/0x8b0 [ 46.583145] snd_pcm_open.part.0+0xdc/0x200 [ 46.588341] snd_pcm_playback_open+0x51/0x80 [ 46.593625] chrdev_open+0xc0/0x250 [ 46.598129] do_dentry_open+0x15f/0x430 [ 46.602981] path_openat+0x75e/0xa80 [ 46.607575] do_filp_open+0xb2/0x160 [ 46.612162] do_sys_openat2+0x9a/0x160 [ 46.616922] __x64_sys_openat+0x53/0xa0 [ 46.621767] do_syscall_64+0x38/0x90 [ 46.626352] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 46.632414] other info that might help us debug this:[ 46.641862] Chain exists of: &slave->sdw_dev_lock --> &card->controls_rwsem --> &card->pcm_mutex[ 46.655145] Possible unsafe locking scenario:[ 46.662048] CPU0 CPU1 [ 46.667080] ---- ---- [ 46.672108] lock(&card->pcm_mutex); [ 46.676267] lock(&card->controls_rwsem); [ 46.683382] lock(&card->pcm_mutex); [ 46.690063] lock(&slave->sdw_dev_lock); [ 46.694574] *** DEADLOCK ***[ 46.701942] 2 locks held by mpg123/1130: [ 46.706356] #0: ffff8b4457b22b90 (&pcm->open_mutex){+.+.}-{3:3}, at: snd_pcm_open.part.0+0xc9/0x200 [ 46.715999] #1: ffffffffc1455310 (&card->pcm_mutex){+.+.}-{3:3}, at: dpcm_fe_dai_open+0x49/0x830 [ 46.725390] stack backtrace: [ 46.730752] CPU: 0 PID: 1130 Comm: mpg123 Tainted: G E 6.1.0-rc4-jamerson #1 [ 46.739703] Hardware name: AAEON UP-WHL01/UP-WHL01, BIOS UPW1AM19 11/10/2020 [ 46.747270] Call Trace: [ 46.750239] [ 46.752857] dump_stack_lvl+0x56/0x73 [ 46.757045] check_noncircular+0x102/0x120 [ 46.761664] __lock_acquire+0x1121/0x1df0 [ 46.766197] lock_acquire+0xd5/0x300 [ 46.770292] ? sdw_update_slave_status+0x26/0x70 [ 46.775432] ? lock_is_held_type+0xe2/0x140 [ 46.780143] __mutex_lock+0x94/0x920 [ 46.784241] ? sdw_update_slave_status+0x26/0x70 [ 46.789387] ? find_held_lock+0x2b/0x80 [ 46.793750] ? sdw_update_slave_status+0x26/0x70 [ 46.798894] ? lock_release+0x147/0x2f0 [ 46.803262] ? lockdep_init_map_type+0x47/0x250 [ 46.808315] ? sdw_update_slave_status+0x26/0x70 [ 46.813456] sdw_update_slave_status+0x26/0x70 [ 46.818422] sdw_clear_slave_status+0xd8/0xe0 [ 46.823302] ? pm_generic_runtime_suspend+0x30/0x30 [ 46.828706] intel_resume_runtime+0x139/0x2a0 [ 46.833583] ? _raw_spin_unlock_irq+0x24/0x50 [ 46.838462] ? pm_generic_runtime_suspend+0x30/0x30 [ 46.843866] __rpm_callback+0x41/0x120 [ 46.848142] ? pm_generic_runtime_suspend+0x30/0x30 [ 46.853550] rpm_callback+0x5d/0x70 [ 46.857568] rpm_resume+0x531/0x7e0 [ 46.861578] ? _raw_spin_lock_irqsave+0x62/0x70 [ 46.866634] __pm_runtime_resume+0x4a/0x80 [ 46.871258] snd_soc_pcm_component_pm_runtime_get+0x2f/0xc0 [ 46.877358] __soc_pcm_open+0x62/0x520 [ 46.881634] ? dpcm_add_paths.isra.0+0x35d/0x4c0 [ 46.886784] dpcm_be_dai_startup+0x116/0x210 [ 46.891592] dpcm_fe_dai_open+0xf7/0x830 [ 46.896046] ? debug_mutex_init+0x33/0x50 [ 46.900591] snd_pcm_open_substream+0x54a/0x8b0 [ 46.905658] snd_pcm_open.part.0+0xdc/0x200 [ 46.910376] ? wake_up_q+0x90/0x90 [ 46.914312] snd_pcm_playback_open+0x51/0x80 [ 46.919118] chrdev_open+0xc0/0x250 [ 46.923147] ? cdev_device_add+0x90/0x90 [ 46.927608] do_dentry_open+0x15f/0x430 [ 46.931976] path_openat+0x75e/0xa80 [ 46.936086] do_filp_open+0xb2/0x160 [ 46.940194] ? lock_release+0x147/0x2f0 [ 46.944563] ? _raw_spin_unlock+0x29/0x50 [ 46.949101] do_sys_openat2+0x9a/0x160 [ 46.953377] __x64_sys_openat+0x53/0xa0 [ 46.957733] do_syscall_64+0x38/0x90 [ 46.961829] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 46.967402] RIP: 0033:0x7fa6397ccd3b [ 46.971506] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 4c 24 28 64 48 33 0c 25 [ 46.991413] RSP: 002b:00007fff838e8990 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 [ 46.999580] RAX: ffffffffffffffda RBX: 0000000000080802 RCX: 00007fa6397ccd3b [ 47.007311] RDX: 0000000000080802 RSI: 00007fff838e8b50 RDI: 00000000ffffff9c [ 47.015047] RBP: 00007fff838e8b50 R08: 0000000000000000 R09: 0000000000000011 [ 47.022787] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080802 [ 47.030539] R13: 0000000000000004 R14: 0000000000000000 R15: 00007fff838e8b50 [ 47.038289] Signed-off-by: Richard Fitzgerald --- Changes since V1: Only changes are to the commit message - Rewrite to try to make the explanation clearer - Include a sample lockdep assert --- drivers/soundwire/bus_type.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c index 04b3529f8929..963498db0fd2 100644 --- a/drivers/soundwire/bus_type.c +++ b/drivers/soundwire/bus_type.c @@ -105,20 +105,19 @@ static int sdw_drv_probe(struct device *dev) if (ret) return ret; - mutex_lock(&slave->sdw_dev_lock); - ret = drv->probe(slave, id); if (ret) { name = drv->name; if (!name) name = drv->driver.name; - mutex_unlock(&slave->sdw_dev_lock); dev_err(dev, "Probe of %s failed: %d\n", name, ret); dev_pm_domain_detach(dev, false); return ret; } + mutex_lock(&slave->sdw_dev_lock); + /* device is probed so let's read the properties now */ if (drv->ops && drv->ops->read_prop) drv->ops->read_prop(slave); @@ -167,14 +166,12 @@ static int sdw_drv_remove(struct device *dev) int ret = 0; mutex_lock(&slave->sdw_dev_lock); - slave->probed = false; + mutex_unlock(&slave->sdw_dev_lock); if (drv->remove) ret = drv->remove(slave); - mutex_unlock(&slave->sdw_dev_lock); - dev_pm_domain_detach(dev, false); return ret;