-----Original Message----- From: Intel-gfx <[email protected]> On Behalf Of Rodrigo Vivi Sent: Friday, August 30, 2024 11:35 AM To: [email protected]; [email protected] Cc: Vivi, Rodrigo <[email protected]>; Deak, Imre <[email protected]> Subject: [PATCH 2/2] drm/xe/display: Avoid encoder_suspend at runtime suspend > > Fix circular locking dependency on runtime suspend. > > <4> [74.952215] ====================================================== > <4> [74.952217] WARNING: possible circular locking dependency detected > <4> [74.952219] 6.10.0-rc7-xe #1 Not tainted > <4> [74.952221] ------------------------------------------------------ > <4> [74.952223] kworker/7:1/82 is trying to acquire lock: > <4> [74.952226] ffff888120548488 (&dev->mode_config.mutex){+.+.}-{3:3}, at: > drm_modeset_lock_all+0x40/0x1e0 [drm] > <4> [74.952260] > but task is already holding lock: > <4> [74.952262] ffffffffa0ae59c0 (xe_pm_runtime_lockdep_map){+.+.}-{0:0}, at: > xe_pm_runtime_suspend+0x2f/0x340 [xe] > <4> [74.952322] > which lock already depends on the new lock. > > The commit b1d90a86 ("drm/xe: Use the encoder suspend helper also used > by the i915 driver") didn't do anything wrong. It actually fixed a > critical bug, because the encoder_suspend was never getting actually > called because it was returning if (has_display(xe)) instead of > if (!has_display(xe)). However, this ended up introducing the encoder > suspend calls in the runtime routines as well, causing the circular > locking dependency. > > Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2304 > Fixes: b1d90a862c89 ("drm/xe: Use the encoder suspend helper also used by the > i915 driver") > Cc: Imre Deak <[email protected]> > Signed-off-by: Rodrigo Vivi <[email protected]>
LGTM. Reviewed-by: Jonathan Cavitt <[email protected]> -Jonathan Cavitt > --- > drivers/gpu/drm/xe/display/xe_display.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/xe/display/xe_display.c > b/drivers/gpu/drm/xe/display/xe_display.c > index ae92012253f8..75736faf2a80 100644 > --- a/drivers/gpu/drm/xe/display/xe_display.c > +++ b/drivers/gpu/drm/xe/display/xe_display.c > @@ -345,10 +345,10 @@ void xe_display_pm_suspend(struct xe_device *xe, bool > runtime) > > intel_hpd_cancel_work(xe); > > - if (!runtime && has_display(xe)) > + if (!runtime && has_display(xe)) { > intel_display_driver_suspend_access(xe); > - > - intel_encoder_suspend_all(&xe->display); > + intel_encoder_suspend_all(&xe->display); > + } > > intel_opregion_suspend(display, s2idle ? PCI_D1 : PCI_D3cold); > > -- > 2.46.0 > >
