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Richard Fitzgerald 3dca1f89ae soundwire: bus_type: Avoid lockdep assert in sdw_drv_probe()
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]  <TASK>
[   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]  </TASK>

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20230123172520.339367-1-rf@opensource.cirrus.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
History 2023-01-31 17:33:11 +05:30
arch treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
block treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto This update includes the following changes: 2022-12-14 12:31:09 -08:00
Documentation kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
drivers soundwire: bus_type: Avoid lockdep assert in sdw_drv_probe() 2023-01-31 17:33:11 +05:30
fs treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
include soundwire: Provide build stubs for common functions 2023-01-09 21:46:27 +05:30
init Kbuild updates for v6.2 2022-12-19 12:33:32 -06:00
io_uring io_uring/net: fix cleanup after recycle 2022-12-19 08:28:28 -07:00
ipc Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
kernel kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
lib test_maple_tree: add test for mas_spanning_rebalance() on insufficient data 2022-12-21 14:31:52 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm hugetlb: really allocate vma lock for all sharable vmas 2022-12-21 14:31:52 -08:00
net treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
rust rust: types: add Opaque type 2022-12-04 01:59:16 +01:00
samples Char/Misc driver changes for 6.2-rc1 2022-12-16 03:49:24 -08:00
scripts modernize use of grep in coccicheck 2022-12-23 13:56:41 -08:00
security kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
sound ASoC/soundwire: remove is_sdca boolean property 2023-01-09 21:37:40 +05:30
tools perf tools fixes and improvements for v6.2: 2nd batch 2022-12-22 11:07:29 -08:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt ARM64: 2022-12-15 11:12:21 -08:00
.clang-format iommufd for 6.2 2022-12-14 09:15:43 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: Cleanup DT Overlay intermediate files as appropriate 2022-11-18 14:45:30 -06:00
.mailmap Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: zram: zsmalloc: Add an additional co-maintainer 2022-12-15 16:37:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS io_uring-6.2-2022-12-19 2022-12-21 16:28:25 -08:00
Makefile Linux 6.2-rc1 2022-12-25 13:41:39 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.