On Thu, Jul 17, 2025 at 01:54:49PM +0200, Maarten Lankhorst wrote: > Hey, > > When I looked at enabling -RT for Xe yesterday, I noticed this trace. > > https://intel-gfx-ci.01.org/tree/intel-xe/xe-pw-151626v2/shard-bmg-6/igt@kms_cursor_crc@cursor-susp...@pipe-d-hdmi-a-3.html#dmesg-warnings488 > > I independently discovered the bug as a result, and sent this patch to > actually disable the irqs. > > https://patchwork.freedesktop.org/series/151728/
Display IRQs in general are still needed by the encoder suspend/shutdown hooks, for things like DP AUX and I2C. So I'd only block the HPD IRQs right before intel_hpd_cancel_work() and disable all the display IRQs only after the encoder hooks. > If you have a reproducer, can you confirm this fixes it? > > Kind regards, > ~Maarten > > Den 2025-07-17 kl. 10:54, skrev Dibin Moolakadan Subrahmanian: > > It has been observed that during `xe_display_pm_suspend()` execution, > > an HPD interrupt can still be triggered, resulting in `dig_port_work` > > being scheduled. The issue arises when this work executes after > > `xe_display_pm_suspend_late()`, by which time the display is fully > > suspended. > > > > This can lead to errors such as "DC state mismatch", as the dig_port > > work accesses display resources that are no longer available or > > powered. > > > > To address this, introduce 'intel_hpd_block_all_encoders()' and > > 'intel_hpd_unblock_all_encoders()' functions, which iterate over all > > encoders and block/unblock HPD respectively. > > > > These are used to: > > - Block HPD IRQs before calling 'intel_hpd_cancel_work' in suspend > > - Unblock HPD IRQs after 'intel_hpd_init' in resume > > > > This will prevent 'dig_port_work' being scheduled during display > > suspend. > > > > Continuation of previous patch discussion: > > https://patchwork.freedesktop.org/patch/663964/ > > > > Signed-off-by: Dibin Moolakadan Subrahmanian > > <dibin.moolakadan.subrahman...@intel.com> > > --- > > drivers/gpu/drm/i915/display/intel_hotplug.c | 24 ++++++++++++++++++-- > > drivers/gpu/drm/i915/display/intel_hotplug.h | 2 ++ > > drivers/gpu/drm/xe/display/xe_display.c | 4 ++++ > > 3 files changed, 28 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c > > b/drivers/gpu/drm/i915/display/intel_hotplug.c > > index 265aa97fcc75..7ffd8ded1c26 100644 > > --- a/drivers/gpu/drm/i915/display/intel_hotplug.c > > +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c > > @@ -223,6 +223,28 @@ queue_detection_work(struct intel_display *display, > > struct work_struct *work) > > return queue_work(display->wq.unordered, work); > > } > > > > +void intel_hpd_unblock_all_encoders(struct intel_display *display) > > +{ > > + struct intel_encoder *encoder; > > + > > + if (!HAS_DISPLAY(display)) > > + return; > > + > > + for_each_intel_encoder(display->drm, encoder) > > + intel_hpd_unblock(encoder); > > +} > > + > > +void intel_hpd_block_all_encoders(struct intel_display *display) > > +{ > > + struct intel_encoder *encoder; > > + > > + if (!HAS_DISPLAY(display)) > > + return; > > + > > + for_each_intel_encoder(display->drm, encoder) > > + intel_hpd_block(encoder); > > +} > > + > > static void > > intel_hpd_irq_storm_switch_to_polling(struct intel_display *display) > > { > > @@ -971,8 +993,6 @@ void intel_hpd_cancel_work(struct intel_display > > *display) > > > > spin_lock_irq(&display->irq.lock); > > > > - drm_WARN_ON(display->drm, get_blocked_hpd_pin_mask(display)); > > - > > display->hotplug.long_hpd_pin_mask = 0; > > display->hotplug.short_hpd_pin_mask = 0; > > display->hotplug.event_bits = 0; > > diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.h > > b/drivers/gpu/drm/i915/display/intel_hotplug.h > > index edc41c9d3d65..3938c93d2385 100644 > > --- a/drivers/gpu/drm/i915/display/intel_hotplug.h > > +++ b/drivers/gpu/drm/i915/display/intel_hotplug.h > > @@ -34,5 +34,7 @@ void intel_hpd_debugfs_register(struct intel_display > > *display); > > void intel_hpd_enable_detection_work(struct intel_display *display); > > void intel_hpd_disable_detection_work(struct intel_display *display); > > bool intel_hpd_schedule_detection(struct intel_display *display); > > +void intel_hpd_block_all_encoders(struct intel_display *display); > > +void intel_hpd_unblock_all_encoders(struct intel_display *display); > > > > #endif /* __INTEL_HOTPLUG_H__ */ > > diff --git a/drivers/gpu/drm/xe/display/xe_display.c > > b/drivers/gpu/drm/xe/display/xe_display.c > > index e2e0771cf274..51584ea3ed09 100644 > > --- a/drivers/gpu/drm/xe/display/xe_display.c > > +++ b/drivers/gpu/drm/xe/display/xe_display.c > > @@ -340,6 +340,8 @@ void xe_display_pm_suspend(struct xe_device *xe) > > > > xe_display_flush_cleanup_work(xe); > > > > + intel_hpd_block_all_encoders(display); > > + > > intel_hpd_cancel_work(display); > > > > if (has_display(xe)) { > > @@ -471,6 +473,8 @@ void xe_display_pm_resume(struct xe_device *xe) > > > > intel_hpd_init(display); > > > > + intel_hpd_unblock_all_encoders(display); > > + > > if (has_display(xe)) { > > intel_display_driver_resume(display); > > drm_kms_helper_poll_enable(&xe->drm); >
