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Bjørn Mork authored
commit e2c8b870 moved modeset locking inside resume/suspend functions, but missed a code path only executed on lid close/open on older hardware. The result was a deadlock when closing and opening the lid without suspending on such hardware: ============================================= [ INFO: possible recursive locking detected ] 4.6.0-rc1 #385 Not tainted --------------------------------------------- kworker/0:3/88 is trying to acquire lock: (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffffa063e6a4>] intel_display_resume+0x4a/0x12f [i915] but task is already holding lock: (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffffa02d0d4f>] drm_modeset_lock_all+0x3e/0xa6 [drm] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev->mode_config.mutex); lock(&dev->mode_config.mutex); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by kworker/0:3/88: #0: ("kacpi_notify"){++++.+}, at: [<ffffffff81068dfc>] process_one_work+0x14a/0x50b #1: ((&dpc->work)#2){+.+.+.}, at: [<ffffffff81068dfc>] process_one_work+0x14a/0x50b #2: ((acpi_lid_notifier).rwsem){++++.+}, at: [<ffffffff8106f874>] __blocking_notifier_call_chain+0x34/0x65 #3: (&dev_priv->modeset_restore_lock){+.+.+.}, at: [<ffffffffa0664cf6>] intel_lid_notify+0x3c/0xd9 [i915] #4: (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffffa02d0d4f>] drm_modeset_lock_all+0x3e/0xa6 [drm] #5: (crtc_ww_class_acquire){+.+.+.}, at: [<ffffffffa02d0d59>] drm_modeset_lock_all+0x48/0xa6 [drm] #6: (crtc_ww_class_mutex){+.+.+.}, at: [<ffffffffa02d0b2a>] modeset_lock+0x13c/0x1cd [drm] stack backtrace: CPU: 0 PID: 88 Comm: kworker/0:3 Not tainted 4.6.0-rc1 #385 Hardware name: LENOVO 2776LEG/2776LEG, BIOS 6EET55WW (3.15 ) 12/19/2011 Workqueue: kacpi_notify acpi_os_execute_deferred 0000000000000000 ffff88022fd5f990 ffffffff8124af06 ffffffff825b39c0 ffffffff825b39c0 ffff88022fd5fa60 ffffffff8108f547 ffff88022fd5fa70 000000008108e817 ffff880230236cc0 0000000000000000 ffffffff825b39c0 Call Trace: [<ffffffff8124af06>] dump_stack+0x67/0x90 [<ffffffff8108f547>] __lock_acquire+0xdb5/0xf71 [<ffffffff8108bd2c>] ? look_up_lock_class+0xbe/0x10a [<ffffffff8108fae2>] lock_acquire+0x137/0x1cb [<ffffffff8108fae2>] ? lock_acquire+0x137/0x1cb [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915] [<ffffffff8148202f>] mutex_lock_nested+0x7e/0x3a4 [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915] [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915] [<ffffffffa02d0b2a>] ? modeset_lock+0x13c/0x1cd [drm] [<ffffffffa063e6a4>] intel_display_resume+0x4a/0x12f [i915] [<ffffffffa063e6a4>] ? intel_display_resume+0x4a/0x12f [i915] [<ffffffffa02d0b2a>] ? modeset_lock+0x13c/0x1cd [drm] [<ffffffffa02d0b2a>] ? modeset_lock+0x13c/0x1cd [drm] [<ffffffffa02d0bf7>] ? drm_modeset_lock+0x17/0x24 [drm] [<ffffffffa02d0c8b>] ? drm_modeset_lock_all_ctx+0x87/0xa1 [drm] [<ffffffffa0664d6a>] intel_lid_notify+0xb0/0xd9 [i915] [<ffffffff8106f4c6>] notifier_call_chain+0x4a/0x6c [<ffffffff8106f88d>] __blocking_notifier_call_chain+0x4d/0x65 [<ffffffff8106f8b9>] blocking_notifier_call_chain+0x14/0x16 [<ffffffffa0011215>] acpi_lid_send_state+0x83/0xad [button] [<ffffffffa00112a6>] acpi_button_notify+0x41/0x132 [button] [<ffffffff812b07df>] acpi_device_notify+0x19/0x1b [<ffffffff812c8570>] acpi_ev_notify_dispatch+0x49/0x64 [<ffffffff812ab9fb>] acpi_os_execute_deferred+0x14/0x20 [<ffffffff81068f17>] process_one_work+0x265/0x50b [<ffffffff810696f5>] worker_thread+0x1fc/0x2dd [<ffffffff810694f9>] ? rescuer_thread+0x309/0x309 [<ffffffff810694f9>] ? rescuer_thread+0x309/0x309 [<ffffffff8106e2d6>] kthread+0xe0/0xe8 [<ffffffff8107bc47>] ? local_clock+0x19/0x22 [<ffffffff81484f42>] ret_from_fork+0x22/0x40 [<ffffffff8106e1f6>] ? kthread_create_on_node+0x1b5/0x1b5 Fixes: e2c8b870 ("drm/i915: Use atomic helpers for suspend, v2.") Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by:
Bjørn Mork <bjorn@mork.no> Signed-off-by:
Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1459328913-13719-1-git-send-email-bjorn@mork.no
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