radeon's ->runtime_suspend hook calls drm_kms_helper_poll_disable(),
which waits for the output poll worker to finish if it's running.
The output poll worker meanwhile calls pm_runtime_get_sync() in
radeon's ->detect hooks, which waits for the ongoing suspend to finish,
causing a deadlock.
Fix by not acquiring a runtime PM ref if the ->detect hooks are called
in the output poll worker's context. This is safe because the poll
worker is only enabled while runtime active and we know that
->runtime_suspend waits for it to finish.
Stack trace for posterity:
INFO: task kworker/0:3:31847 blocked for more than 120 seconds
Workqueue: events output_poll_execute [drm_kms_helper]
Call Trace:
schedule+0x3c/0x90
rpm_resume+0x1e2/0x690
__pm_runtime_resume+0x3f/0x60
radeon_lvds_detect+0x39/0xf0 [radeon]
output_poll_execute+0xda/0x1e0 [drm_kms_helper]
process_one_work+0x14b/0x440
worker_thread+0x48/0x4a0
INFO: task kworker/2:0:10493 blocked for more than 120 seconds.
Workqueue: pm pm_runtime_work
Call Trace:
schedule+0x3c/0x90
schedule_timeout+0x1b3/0x240
wait_for_common+0xc2/0x180
wait_for_completion+0x1d/0x20
flush_work+0xfc/0x1a0
__cancel_work_timer+0xa5/0x1d0
cancel_delayed_work_sync+0x13/0x20
drm_kms_helper_poll_disable+0x1f/0x30 [drm_kms_helper]
radeon_pmops_runtime_suspend+0x3d/0xa0 [radeon]
pci_pm_runtime_suspend+0x61/0x1a0
vga_switcheroo_runtime_suspend+0x21/0x70
__rpm_callback+0x32/0x70
rpm_callback+0x24/0x80
rpm_suspend+0x12b/0x640
pm_runtime_work+0x6f/0xb0
process_one_work+0x14b/0x440
worker_thread+0x48/0x4a0
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94147
Fixes:
|
||
|---|---|---|
| .. | ||
| drm | ||
| host1x | ||
| ipu-v3 | ||
| vga | ||
| Makefile | ||