Re: Adreno devfreq lockdep splat with 6.3-rc2

[Johan Hovold <johan@kernel.org>]

Hi Rob,

Have you had a chance to look at this regression yet? It prevents us
from using lockdep on the X13s as it is disabled as soon as we start
the GPU.

On Wed, Mar 15, 2023 at 10:19:21AM +0100, Johan Hovold wrote:
> 
> Since 6.3-rc2 (or possibly -rc1), I'm now seeing the below
> devfreq-related lockdep splat.
> 
> I noticed that you posted a fix for something similar here:
> 
> 	https://lore.kernel.org/r/20230312204150.1353517-9-robdclark@gmail.com
> 
> but that particular patch makes no difference.
> 
> From skimming the calltraces below and qos/devfreq related changes in
> 6.3-rc1 it seems like this could be related to:
> 
> 	fadcc3ab1302 ("drm/msm/gpu: Bypass PM QoS constraint for idle clamp")

Below is an updated splat from 6.4-rc5.

Johan

[ 2941.931507] ======================================================
[ 2941.931509] WARNING: possible circular locking dependency detected
[ 2941.931513] 6.4.0-rc5 #64 Not tainted
[ 2941.931516] ------------------------------------------------------
[ 2941.931518] ring0/359 is trying to acquire lock:
[ 2941.931520] ffff63310e35c078 (&devfreq->lock){+.+.}-{3:3}, at: qos_min_notifier_call+0x28/0x88
[ 2941.931541] 
               but task is already holding lock:
[ 2941.931543] ffff63310e3cace8 (&(c->notifiers)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x30/0x70
[ 2941.931553] 
               which lock already depends on the new lock.

[ 2941.931555] 
               the existing dependency chain (in reverse order) is:
[ 2941.931556] 
               -> #4 (&(c->notifiers)->rwsem){++++}-{3:3}:
[ 2941.931562]        down_write+0x50/0x198
[ 2941.931567]        blocking_notifier_chain_register+0x30/0x8c
[ 2941.931570]        freq_qos_add_notifier+0x68/0x7c
[ 2941.931574]        dev_pm_qos_add_notifier+0xa0/0xf8
[ 2941.931579]        devfreq_add_device.part.0+0x360/0x5a4
[ 2941.931583]        devm_devfreq_add_device+0x74/0xe0
[ 2941.931587]        msm_devfreq_init+0xa0/0x154 [msm]
[ 2941.931624]        msm_gpu_init+0x2fc/0x588 [msm]
[ 2941.931649]        adreno_gpu_init+0x160/0x2d0 [msm]
[ 2941.931675]        a6xx_gpu_init+0x2c0/0x74c [msm]
[ 2941.931699]        adreno_bind+0x180/0x290 [msm]
[ 2941.931723]        component_bind_all+0x124/0x288
[ 2941.931728]        msm_drm_bind+0x1d8/0x6cc [msm]
[ 2941.931752]        try_to_bring_up_aggregate_device+0x1ec/0x2f4
[ 2941.931755]        __component_add+0xa8/0x194
[ 2941.931758]        component_add+0x14/0x20
[ 2941.931761]        dp_display_probe+0x2b4/0x474 [msm]
[ 2941.931785]        platform_probe+0x68/0xd8
[ 2941.931789]        really_probe+0x184/0x3c8
[ 2941.931792]        __driver_probe_device+0x7c/0x16c
[ 2941.931794]        driver_probe_device+0x3c/0x110
[ 2941.931797]        __device_attach_driver+0xbc/0x158
[ 2941.931800]        bus_for_each_drv+0x84/0xe0
[ 2941.931802]        __device_attach+0xa8/0x1d4
[ 2941.931805]        device_initial_probe+0x14/0x20
[ 2941.931807]        bus_probe_device+0xb0/0xb4
[ 2941.931810]        deferred_probe_work_func+0xa0/0xf4
[ 2941.931812]        process_one_work+0x288/0x5bc
[ 2941.931816]        worker_thread+0x74/0x450
[ 2941.931818]        kthread+0x124/0x128
[ 2941.931822]        ret_from_fork+0x10/0x20
[ 2941.931826] 
               -> #3 (dev_pm_qos_mtx){+.+.}-{3:3}:
[ 2941.931831]        __mutex_lock+0xa0/0x840
[ 2941.931833]        mutex_lock_nested+0x24/0x30
[ 2941.931836]        dev_pm_qos_remove_notifier+0x34/0x140
[ 2941.931838]        genpd_remove_device+0x3c/0x174
[ 2941.931841]        genpd_dev_pm_detach+0x78/0x1b4
[ 2941.931844]        dev_pm_domain_detach+0x24/0x34
[ 2941.931846]        a6xx_gmu_remove+0x34/0xc4 [msm]
[ 2941.931869]        a6xx_destroy+0xd0/0x160 [msm]
[ 2941.931892]        adreno_unbind+0x40/0x64 [msm]
[ 2941.931916]        component_unbind+0x38/0x6c
[ 2941.931919]        component_unbind_all+0xc8/0xd4
[ 2941.931921]        msm_drm_uninit.isra.0+0x150/0x1c4 [msm]
[ 2941.931945]        msm_drm_bind+0x310/0x6cc [msm]
[ 2941.931967]        try_to_bring_up_aggregate_device+0x1ec/0x2f4
[ 2941.931970]        __component_add+0xa8/0x194
[ 2941.931973]        component_add+0x14/0x20
[ 2941.931976]        dp_display_probe+0x2b4/0x474 [msm]
[ 2941.932000]        platform_probe+0x68/0xd8
[ 2941.932003]        really_probe+0x184/0x3c8
[ 2941.932005]        __driver_probe_device+0x7c/0x16c
[ 2941.932008]        driver_probe_device+0x3c/0x110
[ 2941.932011]        __device_attach_driver+0xbc/0x158
[ 2941.932014]        bus_for_each_drv+0x84/0xe0
[ 2941.932016]        __device_attach+0xa8/0x1d4
[ 2941.932018]        device_initial_probe+0x14/0x20
[ 2941.932021]        bus_probe_device+0xb0/0xb4
[ 2941.932023]        deferred_probe_work_func+0xa0/0xf4
[ 2941.932026]        process_one_work+0x288/0x5bc
[ 2941.932028]        worker_thread+0x74/0x450
[ 2941.932031]        kthread+0x124/0x128
[ 2941.932035]        ret_from_fork+0x10/0x20
[ 2941.932037] 
               -> #2 (&gmu->lock){+.+.}-{3:3}:
[ 2941.932043]        __mutex_lock+0xa0/0x840
[ 2941.932045]        mutex_lock_nested+0x24/0x30
[ 2941.932047]        a6xx_gpu_set_freq+0x30/0x5c [msm]
[ 2941.932071]        msm_devfreq_target+0xb8/0x1a8 [msm]
[ 2941.932094]        devfreq_set_target+0x84/0x27c
[ 2941.932098]        devfreq_update_target+0xc4/0xec
[ 2941.932102]        devfreq_monitor+0x38/0x170
[ 2941.932105]        process_one_work+0x288/0x5bc
[ 2941.932108]        worker_thread+0x74/0x450
[ 2941.932110]        kthread+0x124/0x128
[ 2941.932113]        ret_from_fork+0x10/0x20
[ 2941.932116] 
               -> #1 (&df->lock){+.+.}-{3:3}:
[ 2941.932121]        __mutex_lock+0xa0/0x840
[ 2941.932124]        mutex_lock_nested+0x24/0x30
[ 2941.932126]        msm_devfreq_get_dev_status+0x48/0x134 [msm]
[ 2941.932149]        devfreq_simple_ondemand_func+0x3c/0x144
[ 2941.932153]        devfreq_update_target+0x4c/0xec
[ 2941.932157]        devfreq_monitor+0x38/0x170
[ 2941.932160]        process_one_work+0x288/0x5bc
[ 2941.932162]        worker_thread+0x74/0x450
[ 2941.932165]        kthread+0x124/0x128
[ 2941.932168]        ret_from_fork+0x10/0x20
[ 2941.932171] 
               -> #0 (&devfreq->lock){+.+.}-{3:3}:
[ 2941.932175]        __lock_acquire+0x13d8/0x2188
[ 2941.932178]        lock_acquire+0x1e8/0x310
[ 2941.932180]        __mutex_lock+0xa0/0x840
[ 2941.932182]        mutex_lock_nested+0x24/0x30
[ 2941.932184]        qos_min_notifier_call+0x28/0x88
[ 2941.932188]        notifier_call_chain+0xa0/0x17c
[ 2941.932190]        blocking_notifier_call_chain+0x48/0x70
[ 2941.932193]        pm_qos_update_target+0xdc/0x1d0
[ 2941.932195]        freq_qos_apply+0x68/0x74
[ 2941.932198]        apply_constraint+0x100/0x148
[ 2941.932201]        __dev_pm_qos_update_request+0xb8/0x1fc
[ 2941.932203]        dev_pm_qos_update_request+0x3c/0x64
[ 2941.932206]        msm_devfreq_active+0xf8/0x194 [msm]
[ 2941.932227]        msm_gpu_submit+0x18c/0x1a8 [msm]
[ 2941.932249]        msm_job_run+0x98/0x11c [msm]
[ 2941.932272]        drm_sched_main+0x1a0/0x444 [gpu_sched]
[ 2941.932281]        kthread+0x124/0x128
[ 2941.932284]        ret_from_fork+0x10/0x20
[ 2941.932287] 
               other info that might help us debug this:

[ 2941.932289] Chain exists of:
                 &devfreq->lock --> dev_pm_qos_mtx --> &(c->notifiers)->rwsem

[ 2941.932296]  Possible unsafe locking scenario:

[ 2941.932298]        CPU0                    CPU1
[ 2941.932300]        ----                    ----
[ 2941.932301]   rlock(&(c->notifiers)->rwsem);
[ 2941.932304]                                lock(dev_pm_qos_mtx);
[ 2941.932307]                                lock(&(c->notifiers)->rwsem);
[ 2941.932309]   lock(&devfreq->lock);
[ 2941.932312] 
                *** DEADLOCK ***

[ 2941.932313] 4 locks held by ring0/359:
[ 2941.932315]  #0: ffff633110966170 (&gpu->lock){+.+.}-{3:3}, at: msm_job_run+0x8c/0x11c [msm]
[ 2941.932342]  #1: ffff633110966208 (&gpu->active_lock){+.+.}-{3:3}, at: msm_gpu_submit+0xdc/0x1a8 [msm]
[ 2941.932368]  #2: ffffa40da2f91ed0 (dev_pm_qos_mtx){+.+.}-{3:3}, at: dev_pm_qos_update_request+0x30/0x64
[ 2941.932374]  #3: ffff63310e3cace8 (&(c->notifiers)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x30/0x70
[ 2941.932381] 
               stack backtrace:
[ 2941.932383] CPU: 7 PID: 359 Comm: ring0 Not tainted 6.4.0-rc5 #64
[ 2941.932386] Hardware name: LENOVO 21BYZ9SRUS/21BYZ9SRUS, BIOS N3HET53W (1.25 ) 10/12/2022
[ 2941.932389] Call trace:
[ 2941.932391]  dump_backtrace+0x9c/0x11c
[ 2941.932395]  show_stack+0x18/0x24
[ 2941.932398]  dump_stack_lvl+0x60/0xac
[ 2941.932402]  dump_stack+0x18/0x24
[ 2941.932405]  print_circular_bug+0x26c/0x348
[ 2941.932407]  check_noncircular+0x134/0x148
[ 2941.932409]  __lock_acquire+0x13d8/0x2188
[ 2941.932411]  lock_acquire+0x1e8/0x310
[ 2941.932414]  __mutex_lock+0xa0/0x840
[ 2941.932416]  mutex_lock_nested+0x24/0x30
[ 2941.932418]  qos_min_notifier_call+0x28/0x88
[ 2941.932421]  notifier_call_chain+0xa0/0x17c
[ 2941.932424]  blocking_notifier_call_chain+0x48/0x70
[ 2941.932426]  pm_qos_update_target+0xdc/0x1d0
[ 2941.932428]  freq_qos_apply+0x68/0x74
[ 2941.932431]  apply_constraint+0x100/0x148
[ 2941.932433]  __dev_pm_qos_update_request+0xb8/0x1fc
[ 2941.932435]  dev_pm_qos_update_request+0x3c/0x64
[ 2941.932437]  msm_devfreq_active+0xf8/0x194 [msm]
[ 2941.932460]  msm_gpu_submit+0x18c/0x1a8 [msm]
[ 2941.932482]  msm_job_run+0x98/0x11c [msm]
[ 2941.932504]  drm_sched_main+0x1a0/0x444 [gpu_sched]
[ 2941.932511]  kthread+0x124/0x128
[ 2941.932514]  ret_from_fork+0x10/0x20