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Rob Clark 9064662f15 drm/msm/a6xx: Fix GMU lockdep splat 
[ Upstream commit 3136a0f835 ]

For normal GPU devfreq, we need to acquire the GMU lock while already
holding devfreq locks.  But in the teardown path, we were calling
dev_pm_domain_detach() while already holding the GMU lock, resulting in
this lockdep splat:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.4.3-debug+ #3 Not tainted
   ------------------------------------------------------
   ring0/391 is trying to acquire lock:
   ffffff80a025c078 (&devfreq->lock){+.+.}-{3:3}, at: qos_notifier_call+0x30/0x74

   but task is already holding lock:
   ffffff809b8c1ce8 (&(c->notifiers)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x34/0x78

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #4 (&(c->notifiers)->rwsem){++++}-{3:3}:
          down_write+0x58/0x74
          __blocking_notifier_chain_register+0x64/0x84
          blocking_notifier_chain_register+0x1c/0x28
          freq_qos_add_notifier+0x5c/0x7c
          dev_pm_qos_add_notifier+0xd4/0xf0
          devfreq_add_device+0x42c/0x560
          devm_devfreq_add_device+0x6c/0xb8
          msm_devfreq_init+0xa8/0x16c [msm]
          msm_gpu_init+0x368/0x54c [msm]
          adreno_gpu_init+0x248/0x2b0 [msm]
          a6xx_gpu_init+0x2d0/0x384 [msm]
          adreno_bind+0x264/0x2bc [msm]
          component_bind_all+0x124/0x1f4
          msm_drm_bind+0x2d0/0x5f4 [msm]
          try_to_bring_up_aggregate_device+0x88/0x1a4
          __component_add+0xd4/0x128
          component_add+0x1c/0x28
          dp_display_probe+0x37c/0x3c0 [msm]
          platform_probe+0x70/0xc0
          really_probe+0x148/0x280
          __driver_probe_device+0xfc/0x114
          driver_probe_device+0x44/0x100
          __device_attach_driver+0x64/0xdc
          bus_for_each_drv+0xb0/0xd8
          __device_attach+0xe4/0x140
          device_initial_probe+0x1c/0x28
          bus_probe_device+0x44/0xb0
          deferred_probe_work_func+0xb0/0xc8
          process_one_work+0x288/0x3d8
          worker_thread+0x1f0/0x260
          kthread+0xf0/0x100
          ret_from_fork+0x10/0x20

   -> #3 (dev_pm_qos_mtx){+.+.}-{3:3}:
          __mutex_lock+0xc8/0x388
          mutex_lock_nested+0x2c/0x38
          dev_pm_qos_remove_notifier+0x3c/0xc8
          genpd_remove_device+0x40/0x11c
          genpd_dev_pm_detach+0x88/0x130
          dev_pm_domain_detach+0x2c/0x3c
          a6xx_gmu_remove+0x44/0xdc [msm]
          a6xx_destroy+0x7c/0xa4 [msm]
          adreno_unbind+0x50/0x64 [msm]
          component_unbind+0x44/0x64
          component_unbind_all+0xb4/0xbc
          msm_drm_uninit.isra.0+0x124/0x17c [msm]
          msm_drm_bind+0x340/0x5f4 [msm]
          try_to_bring_up_aggregate_device+0x88/0x1a4
          __component_add+0xd4/0x128
          component_add+0x1c/0x28
          dp_display_probe+0x37c/0x3c0 [msm]
          platform_probe+0x70/0xc0
          really_probe+0x148/0x280
          __driver_probe_device+0xfc/0x114
          driver_probe_device+0x44/0x100
          __device_attach_driver+0x64/0xdc
          bus_for_each_drv+0xb0/0xd8
          __device_attach+0xe4/0x140
          device_initial_probe+0x1c/0x28
          bus_probe_device+0x44/0xb0
          deferred_probe_work_func+0xb0/0xc8
          process_one_work+0x288/0x3d8
          worker_thread+0x1f0/0x260
          kthread+0xf0/0x100
          ret_from_fork+0x10/0x20

   -> #2 (&a6xx_gpu->gmu.lock){+.+.}-{3:3}:
          __mutex_lock+0xc8/0x388
          mutex_lock_nested+0x2c/0x38
          a6xx_gpu_set_freq+0x38/0x64 [msm]
          msm_devfreq_target+0x170/0x18c [msm]
          devfreq_set_target+0x90/0x1e4
          devfreq_update_target+0xb4/0xf0
          update_devfreq+0x1c/0x28
          devfreq_monitor+0x3c/0x10c
          process_one_work+0x288/0x3d8
          worker_thread+0x1f0/0x260
          kthread+0xf0/0x100
          ret_from_fork+0x10/0x20

   -> #1 (&df->lock){+.+.}-{3:3}:
          __mutex_lock+0xc8/0x388
          mutex_lock_nested+0x2c/0x38
          msm_devfreq_get_dev_status+0x4c/0x104 [msm]
          devfreq_simple_ondemand_func+0x5c/0x128
          devfreq_update_target+0x68/0xf0
          update_devfreq+0x1c/0x28
          devfreq_monitor+0x3c/0x10c
          process_one_work+0x288/0x3d8
          worker_thread+0x1f0/0x260
          kthread+0xf0/0x100
          ret_from_fork+0x10/0x20

   -> #0 (&devfreq->lock){+.+.}-{3:3}:
          __lock_acquire+0xdf8/0x109c
          lock_acquire+0x234/0x284
          __mutex_lock+0xc8/0x388
          mutex_lock_nested+0x2c/0x38
          qos_notifier_call+0x30/0x74
          qos_min_notifier_call+0x1c/0x28
          notifier_call_chain+0xf4/0x114
          blocking_notifier_call_chain+0x4c/0x78
          pm_qos_update_target+0x184/0x190
          freq_qos_apply+0x4c/0x64
          apply_constraint+0xf8/0xfc
          __dev_pm_qos_update_request+0x138/0x164
          dev_pm_qos_update_request+0x44/0x68
          msm_devfreq_boost+0x40/0x70 [msm]
          msm_devfreq_active+0xc0/0xf0 [msm]
          msm_gpu_submit+0xc8/0x12c [msm]
          msm_job_run+0x88/0x128 [msm]
          drm_sched_main+0x240/0x324 [gpu_sched]
          kthread+0xf0/0x100
          ret_from_fork+0x10/0x20

   other info that might help us debug this:
   Chain exists of:
     &devfreq->lock --> dev_pm_qos_mtx --> &(c->notifiers)->rwsem
    Possible unsafe locking scenario:
          CPU0                    CPU1
          ----                    ----
     rlock(&(c->notifiers)->rwsem);
                                  lock(dev_pm_qos_mtx);
                                  lock(&(c->notifiers)->rwsem);
     lock(&devfreq->lock);

    *** DEADLOCK ***
   4 locks held by ring0/391:
    #0: ffffff809c811170 (&gpu->lock){+.+.}-{3:3}, at: msm_job_run+0x7c/0x128 [msm]
    #1: ffffff809c811208 (&gpu->active_lock){+.+.}-{3:3}, at: msm_gpu_submit+0xa8/0x12c [msm]
    #2: ffffffecbbb46600 (dev_pm_qos_mtx){+.+.}-{3:3}, at: dev_pm_qos_update_request+0x38/0x68
    #3: ffffff809b8c1ce8 (&(c->notifiers)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x34/0x78

   stack backtrace:
   CPU: 6 PID: 391 Comm: ring0 Not tainted 6.4.3debug+ #3
   Hardware name: Google Villager (rev1+) with LTE (DT)
   Call trace:
    dump_backtrace+0xb4/0xf0
    show_stack+0x20/0x30
    dump_stack_lvl+0x60/0x84
    dump_stack+0x18/0x24
    print_circular_bug+0x1cc/0x234
    check_noncircular+0x78/0xac
    __lock_acquire+0xdf8/0x109c
    lock_acquire+0x234/0x284
    __mutex_lock+0xc8/0x388
    mutex_lock_nested+0x2c/0x38
    qos_notifier_call+0x30/0x74
    qos_min_notifier_call+0x1c/0x28
    notifier_call_chain+0xf4/0x114
    blocking_notifier_call_chain+0x4c/0x78
    pm_qos_update_target+0x184/0x190
    freq_qos_apply+0x4c/0x64
    apply_constraint+0xf8/0xfc
    __dev_pm_qos_update_request+0x138/0x164
    dev_pm_qos_update_request+0x44/0x68
    msm_devfreq_boost+0x40/0x70 [msm]
    msm_devfreq_active+0xc0/0xf0 [msm]
    msm_gpu_submit+0xc8/0x12c [msm]
    msm_job_run+0x88/0x128 [msm]
    drm_sched_main+0x240/0x324 [gpu_sched]
    kthread+0xf0/0x100
    ret_from_fork+0x10/0x20

Fix this by only synchronizing access to gmu->initialized.

Fixes: 4cd15a3e8b ("drm/msm/a6xx: Make GPU destroy a bit safer")
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/551171/
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2023-09-13 09:48:16 +02:00
arch arm64: dts: qcom: sm8550-mtp: Add missing supply for L1B regulator 2023-09-13 09:48:16 +02:00
block block: don't allow enabling a cache on devices that don't support it 2023-09-13 09:48:13 +02:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: api - Use work queue in crypto_destroy_instance 2023-09-13 09:48:03 +02:00
Documentation dt-bindings: sc16is7xx: Add property to change GPIO function 2023-09-06 21:25:32 +01:00
drivers drm/msm/a6xx: Fix GMU lockdep splat 2023-09-13 09:48:16 +02:00
fs quota: fix dqput() to follow the guarantees dquot_srcu should provide 2023-09-13 09:48:09 +02:00
include block: don't allow enabling a cache on devices that don't support it 2023-09-13 09:48:13 +02:00
init sched/psi: Select KERNFS as needed 2023-09-13 09:47:58 +02:00
io_uring io_uring: correct check for O_TMPFILE 2023-08-16 18:32:19 +02:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel bpf: Fix check_func_arg_reg_off bug for graph root/node 2023-09-13 09:48:06 +02:00
lib sbitmap: fix batching wakeup 2023-09-13 09:47:55 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm net-memcg: Fix scope of sockmem pressure indicators 2023-09-13 09:48:05 +02:00
net netrom: Deny concurrent connect(). 2023-09-13 09:48:09 +02:00
rust rust: macros: vtable: fix HAS_* redefinition (gen_const_name) 2023-08-23 17:32:36 +02:00
samples samples/bpf: fix broken map lookup probe 2023-09-13 09:48:06 +02:00
scripts scripts/gdb: fix 'lx-lsmod' show the wrong size 2023-09-13 09:48:05 +02:00
security smackfs: Prevent underflow in smk_set_cipso() 2023-09-13 09:48:16 +02:00
sound ASoC: fsl: fsl_qmc_audio: Fix snd_pcm_format_t values handling 2023-09-13 09:48:14 +02:00
tools selftests: memfd: error out test process when child test fails 2023-09-13 09:48:06 +02:00
usr initramfs: Check negative timestamp to prevent broken cpio archive 2023-04-16 17:37:01 +09:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-08-03 10:26:01 +02:00
.clang-format cxl for v6.4 2023-04-30 11:51:51 -07:00
.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 *.dtso files 2023-02-26 15:28:23 +09:00
.gitignore linux-kselftest-kunit-6.4-rc1 2023-04-24 12:31:32 -07:00
.mailmap mailmap: add entries for Ben Dooks 2023-06-19 13:19:35 -07:00
.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: sctp: move Neil to CREDITS 2023-05-12 08:51:32 +01:00
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 Networking fixes for 6.4-rc8, including fixes from ipsec, bpf, 2023-06-22 17:59:51 -07:00
Makefile kbuild: rust_is_available: remove -v option 2023-09-13 09:48:03 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

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.