On Thu, 24 Jul 2025, Maarten Lankhorst <maarten.lankho...@linux.intel.com> wrote: > Hey, > > Den 2025-07-23 kl. 15:19, skrev Rodrigo Vivi: >> On Wed, Jul 23, 2025 at 12:38:08PM +0300, Imre Deak wrote: >>> On Wed, Jul 23, 2025 at 02:59:46PM +0530, Dibin Moolakadan Subrahmanian >>> wrote: >>>> 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_encoder_block_all_hpds' and >>>> 'intel_encoder_unblock_all_hpds' 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 >>>> and shutdown >>>> - 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/ >>>> >>>> Changes in v2: >>>> - Add 'intel_encoder_block_all_hpds' to 'xe_display_pm_shutdown' >>>> - Add 'intel_hpd_cancel_work' to 'xe_display_fini_early' to cancel >>>> any HPD pending work at late driver removal >>>> >>>> Signed-off-by: Dibin Moolakadan Subrahmanian >>>> <dibin.moolakadan.subrahman...@intel.com> >>>> --- >>>> drivers/gpu/drm/i915/display/intel_encoder.c | 23 ++++++++++++++++++++ >>>> drivers/gpu/drm/i915/display/intel_encoder.h | 3 +++ >>>> drivers/gpu/drm/i915/display/intel_hotplug.c | 2 -- >>>> drivers/gpu/drm/xe/display/xe_display.c | 6 +++++ >>>> 4 files changed, 32 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/gpu/drm/i915/display/intel_encoder.c >>>> b/drivers/gpu/drm/i915/display/intel_encoder.c >>>> index 0b7bd26f4339..4e2b77b87678 100644 >>>> --- a/drivers/gpu/drm/i915/display/intel_encoder.c >>>> +++ b/drivers/gpu/drm/i915/display/intel_encoder.c >>>> @@ -8,6 +8,7 @@ >>>> #include "intel_display_core.h" >>>> #include "intel_display_types.h" >>>> #include "intel_encoder.h" >>>> +#include "intel_hotplug.h" >>>> >>>> static void intel_encoder_link_check_work_fn(struct work_struct *work) >>>> { >>>> @@ -37,6 +38,28 @@ void intel_encoder_link_check_queue_work(struct >>>> intel_encoder *encoder, int dela >>>> &encoder->link_check_work, msecs_to_jiffies(delay_ms)); >>>> } >>>> >>>> +void intel_encoder_unblock_all_hpds(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_encoder_block_all_hpds(struct intel_display *display) >>>> +{ >>>> + struct intel_encoder *encoder; >>>> + >>>> + if (!HAS_DISPLAY(display)) >>>> + return; >>>> + >>>> + for_each_intel_encoder(display->drm, encoder) >>>> + intel_hpd_block(encoder); >>>> +} >>>> + >>>> void intel_encoder_suspend_all(struct intel_display *display) >>>> { >>>> struct intel_encoder *encoder; >>>> diff --git a/drivers/gpu/drm/i915/display/intel_encoder.h >>>> b/drivers/gpu/drm/i915/display/intel_encoder.h >>>> index 3fa5589f0b1c..e1d3aeab7c00 100644 >>>> --- a/drivers/gpu/drm/i915/display/intel_encoder.h >>>> +++ b/drivers/gpu/drm/i915/display/intel_encoder.h >>>> @@ -17,4 +17,7 @@ void intel_encoder_link_check_flush_work(struct >>>> intel_encoder *encoder); >>>> void intel_encoder_suspend_all(struct intel_display *display); >>>> void intel_encoder_shutdown_all(struct intel_display *display); >>>> >>>> +void intel_encoder_block_all_hpds(struct intel_display *display); >>>> +void intel_encoder_unblock_all_hpds(struct intel_display *display); >>>> + >>>> #endif /* __INTEL_ENCODER_H__ */ >>>> diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c >>>> b/drivers/gpu/drm/i915/display/intel_hotplug.c >>>> index 265aa97fcc75..c69b535497bf 100644 >>>> --- a/drivers/gpu/drm/i915/display/intel_hotplug.c >>>> +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c >>>> @@ -971,8 +971,6 @@ 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/xe/display/xe_display.c >>>> b/drivers/gpu/drm/xe/display/xe_display.c >>>> index e2e0771cf274..9e984a045059 100644 >>>> --- a/drivers/gpu/drm/xe/display/xe_display.c >>>> +++ b/drivers/gpu/drm/xe/display/xe_display.c >>>> @@ -96,6 +96,7 @@ static void xe_display_fini_early(void *arg) >>>> if (!xe->info.probe_display) >>>> return; >>>> >>>> + intel_hpd_cancel_work(display); >>>> intel_display_driver_remove_nogem(display); >>>> intel_display_driver_remove_noirq(display); >>>> intel_opregion_cleanup(display); >>>> @@ -340,6 +341,8 @@ void xe_display_pm_suspend(struct xe_device *xe) >>>> >>>> xe_display_flush_cleanup_work(xe); >>>> >>>> + intel_encoder_block_all_hpds(display); >>>> + >>>> intel_hpd_cancel_work(display); >>>> >>>> if (has_display(xe)) { >>>> @@ -369,6 +372,7 @@ void xe_display_pm_shutdown(struct xe_device *xe) >>>> } >>>> >>>> xe_display_flush_cleanup_work(xe); >>>> + intel_encoder_block_all_hpds(display); >>> >>> MST still needs HPD IRQs for side-band messaging, so the HPD IRQs must >>> be blocked only after intel_dp_mst_suspend(). >>> >>> Otherwise the patch looks ok to me, so with the above fixed and provided >>> that Maarten is ok to disable all display IRQs only later: >> >> Also probably good to identify the patch as both xe and i915 in the subject >> drm/{i915,xe}/display: >> >> and Maarten or Imre, any preference on which branch to go? any chance of >> conflicting with any of work you might be doing in any side? >> >> From my side I believe that any conflict might be easy to handle, so >> >> Acked-by: Rodrigo Vivi <rodrigo.v...@intel.com> >> >> from either side... >> >>> >>> Reviewed-by: Imre Deak <imre.d...@intel.com> > We had a discussion on this approach, and it seems that completely disabling > interrupts here like in i915 would fail too. > > Reviewed-by: Maarten Lankhorst <maarten.lankho...@linux.intel.com> > > I don't mind either branch. As long as it applies. :-)
Please do not merge through *any* tree. How come you all think it's okay to add this xe specific thing, and make unification harder? intel_encoder_block_all_hpds() is *way* too specific for a high level function. Neither xe nor i915 should never call something like that directly. BR, Jani. -- Jani Nikula, Intel
