• Kuogee Hsieh's avatar
    drm/msm/dp: add fail safe mode outside of event_mutex context · 8b2c181e
    Kuogee Hsieh authored
    There is possible circular locking dependency detected on event_mutex
    (see below logs). This is due to set fail safe mode is done at
    dp_panel_read_sink_caps() within event_mutex scope. To break this
    possible circular locking, this patch move setting fail safe mode
    out of event_mutex scope.
    
    [   23.958078] ======================================================
    [   23.964430] WARNING: possible circular locking dependency detected
    [   23.970777] 5.17.0-rc2-lockdep-00088-g05241de1 #148 Not tainted
    [   23.977219] ------------------------------------------------------
    [   23.983570] DrmThread/1574 is trying to acquire lock:
    [   23.988763] ffffff808423aab0 (&dp->event_mutex){+.+.}-{3:3}, at: msm_dp_displ                                                                             ay_enable+0x58/0x164
    [   23.997895]
    [   23.997895] but task is already holding lock:
    [   24.003895] ffffff808420b280 (&kms->commit_lock[i]/1){+.+.}-{3:3}, at: lock_c                                                                             rtcs+0x80/0x8c
    [   24.012495]
    [   24.012495] which lock already depends on the new lock.
    [   24.012495]
    [   24.020886]
    [   24.020886] the existing dependency chain (in reverse order) is:
    [   24.028570]
    [   24.028570] -> #5 (&kms->commit_lock[i]/1){+.+.}-{3:3}:
    [   24.035472]        __mutex_lock+0xc8/0x384
    [   24.039695]        mutex_lock_nested+0x54/0x74
    [   24.044272]        lock_crtcs+0x80/0x8c
    [   24.048222]        msm_atomic_commit_tail+0x1e8/0x3d0
    [   24.053413]        commit_tail+0x7c/0xfc
    [   24.057452]        drm_atomic_helper_commit+0x158/0x15c
    [   24.062826]        drm_atomic_commit+0x60/0x74
    [   24.067403]        drm_mode_atomic_ioctl+0x6b0/0x908
    [   24.072508]        drm_ioctl_kernel+0xe8/0x168
    [   24.077086]        drm_ioctl+0x320/0x370
    [   24.081123]        drm_compat_ioctl+0x40/0xdc
    [   24.085602]        __arm64_compat_sys_ioctl+0xe0/0x150
    [   24.090895]        invoke_syscall+0x80/0x114
    [   24.095294]        el0_svc_common.constprop.3+0xc4/0xf8
    [   24.100668]        do_el0_svc_compat+0x2c/0x54
    [   24.105242]        el0_svc_compat+0x4c/0xe4
    [   24.109548]        el0t_32_sync_handler+0xc4/0xf4
    [   24.114381]        el0t_32_sync+0x178
    [   24.118688]
    [   24.118688] -> #4 (&kms->commit_lock[i]){+.+.}-{3:3}:
    [   24.125408]        __mutex_lock+0xc8/0x384
    [   24.129628]        mutex_lock_nested+0x54/0x74
    [   24.134204]        lock_crtcs+0x80/0x8c
    [   24.138155]        msm_atomic_commit_tail+0x1e8/0x3d0
    [   24.143345]        commit_tail+0x7c/0xfc
    [   24.147382]        drm_atomic_helper_commit+0x158/0x15c
    [   24.152755]        drm_atomic_commit+0x60/0x74
    [   24.157323]        drm_atomic_helper_set_config+0x68/0x90
    [   24.162869]        drm_mode_setcrtc+0x394/0x648
    [   24.167535]        drm_ioctl_kernel+0xe8/0x168
    [   24.172102]        drm_ioctl+0x320/0x370
    [   24.176135]        drm_compat_ioctl+0x40/0xdc
    [   24.180621]        __arm64_compat_sys_ioctl+0xe0/0x150
    [   24.185904]        invoke_syscall+0x80/0x114
    [   24.190302]        el0_svc_common.constprop.3+0xc4/0xf8
    [   24.195673]        do_el0_svc_compat+0x2c/0x54
    [   24.200241]        el0_svc_compat+0x4c/0xe4
    [   24.204544]        el0t_32_sync_handler+0xc4/0xf4
    [   24.209378]        el0t_32_sync+0x174/0x178
    [   24.213680] -> #3 (crtc_ww_class_mutex){+.+.}-{3:3}:
    [   24.220308]        __ww_mutex_lock.constprop.20+0xe8/0x878
    [   24.225951]        ww_mutex_lock+0x60/0xd0
    [   24.230166]        modeset_lock+0x190/0x19c
    [   24.234467]        drm_modeset_lock+0x34/0x54
    [   24.238953]        drmm_mode_config_init+0x550/0x764
    [   24.244065]        msm_drm_bind+0x170/0x59c
    [   24.248374]        try_to_bring_up_master+0x244/0x294
    [   24.253572]        __component_add+0xf4/0x14c
    [   24.258057]        component_add+0x2c/0x38
    [   24.262273]        dsi_dev_attach+0x2c/0x38
    [   24.266575]        dsi_host_attach+0xc4/0x120
    [   24.271060]        mipi_dsi_attach+0x34/0x48
    [   24.275456]        devm_mipi_dsi_attach+0x28/0x68
    [   24.280298]        ti_sn_bridge_probe+0x2b4/0x2dc
    [   24.285137]        auxiliary_bus_probe+0x78/0x90
    [   24.289893]        really_probe+0x1e4/0x3d8
    [   24.294194]        __driver_probe_device+0x14c/0x164
    [   24.299298]        driver_probe_device+0x54/0xf8
    [   24.304043]        __device_attach_driver+0xb4/0x118
    [   24.309145]        bus_for_each_drv+0xb0/0xd4
    [   24.313628]        __device_attach+0xcc/0x158
    [   24.318112]        device_initial_probe+0x24/0x30
    [   24.322954]        bus_probe_device+0x38/0x9c
    [   24.327439]        deferred_probe_work_func+0xd4/0xf0
    [   24.332628]        process_one_work+0x2f0/0x498
    [   24.337289]        process_scheduled_works+0x44/0x48
    [   24.342391]        worker_thread+0x1e4/0x26c
    [   24.346788]        kthread+0xe4/0xf4
    [   24.350470]        ret_from_fork+0x10/0x20
    [   24.354683]
    [   24.354683]
    [   24.354683] -> #2 (crtc_ww_class_acquire){+.+.}-{0:0}:
    [   24.361489]        drm_modeset_acquire_init+0xe4/0x138
    [   24.366777]        drm_helper_probe_detect_ctx+0x44/0x114
    [   24.372327]        check_connector_changed+0xbc/0x198
    [   24.377517]        drm_helper_hpd_irq_event+0xcc/0x11c
    [   24.382804]        dsi_hpd_worker+0x24/0x30
    [   24.387104]        process_one_work+0x2f0/0x498
    [   24.391762]        worker_thread+0x1d0/0x26c
    [   24.396158]        kthread+0xe4/0xf4
    [   24.399840]        ret_from_fork+0x10/0x20
    [   24.404053]
    [   24.404053] -> #1 (&dev->mode_config.mutex){+.+.}-{3:3}:
    [   24.411032]        __mutex_lock+0xc8/0x384
    [   24.415247]        mutex_lock_nested+0x54/0x74
    [   24.419819]        dp_panel_read_sink_caps+0x23c/0x26c
    [   24.425108]        dp_display_process_hpd_high+0x34/0xd4
    [   24.430570]        dp_display_usbpd_configure_cb+0x30/0x3c
    [   24.436205]        hpd_event_thread+0x2ac/0x550
    [   24.440864]        kthread+0xe4/0xf4
    [   24.444544]        ret_from_fork+0x10/0x20
    [   24.448757]
    [   24.448757] -> #0 (&dp->event_mutex){+.+.}-{3:3}:
    [   24.455116]        __lock_acquire+0xe2c/0x10d8
    [   24.459690]        lock_acquire+0x1ac/0x2d0
    [   24.463988]        __mutex_lock+0xc8/0x384
    [   24.468201]        mutex_lock_nested+0x54/0x74
    [   24.472773]        msm_dp_display_enable+0x58/0x164
    [   24.477789]        dp_bridge_enable+0x24/0x30
    [   24.482273]        drm_atomic_bridge_chain_enable+0x78/0x9c
    [   24.488006]        drm_atomic_helper_commit_modeset_enables+0x1bc/0x244
    [   24.494801]        msm_atomic_commit_tail+0x248/0x3d0
    [   24.499992]        commit_tail+0x7c/0xfc
    [   24.504031]        drm_atomic_helper_commit+0x158/0x15c
    [   24.509404]        drm_atomic_commit+0x60/0x74
    [   24.513976]        drm_mode_atomic_ioctl+0x6b0/0x908
    [   24.519079]        drm_ioctl_kernel+0xe8/0x168
    [   24.523650]        drm_ioctl+0x320/0x370
    [   24.527689]        drm_compat_ioctl+0x40/0xdc
    [   24.532175]        __arm64_compat_sys_ioctl+0xe0/0x150
    [   24.537463]        invoke_syscall+0x80/0x114
    [   24.541861]        el0_svc_common.constprop.3+0xc4/0xf8
    [   24.547235]        do_el0_svc_compat+0x2c/0x54
    [   24.551806]        el0_svc_compat+0x4c/0xe4
    [   24.556106]        el0t_32_sync_handler+0xc4/0xf4
    [   24.560948]        el0t_32_sync+0x174/0x178
    
    Changes in v2:
    -- add circular lockiing trace
    
    Fixes: d4aca422 ("drm/msm/dp:  always add fail-safe mode into connector mode list")
    Signed-off-by: default avatarKuogee Hsieh <quic_khsieh@quicinc.com>
    Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
    Patchwork: https://patchwork.freedesktop.org/patch/481396/
    Link: https://lore.kernel.org/r/1649451894-554-1-git-send-email-quic_khsieh@quicinc.comSigned-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
    Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
    8b2c181e
dp_panel.c 11.7 KB