Commit 6e2c8fbc authored by Dibin Moolakadan Subrahmanian's avatar Dibin Moolakadan Subrahmanian Committed by Imre Deak
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drm/{i915,xe}/display: Block hpd during suspend 

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'.(Imre
   Deak)
 - Add 'intel_hpd_cancel_work' to 'xe_display_fini_early' to cancel
   any HPD pending work at late driver removal. (Imre Deak)

Changes in v3:
 - Move 'intel_encoder_block_all_hpds' after intel_dp_mst_suspend
   in 'xe_display_pm_shutdown'.(Imre Deak)

Signed-off-by: default avatarDibin Moolakadan Subrahmanian <dibin.moolakadan.subrahmanian@intel.com>
Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: default avatarJani Nikula <jani.nikula@intel.com>
Acked-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://lore.kernel.org/r/20250724083928.2298199-1-dibin.moolakadan.subrahmanian@intel.com
parent 7b410651

drivers/gpu/drm/i915/display/intel_encoder.c

+23 −0
Original line number Diff line number Diff line
@@ -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;

drivers/gpu/drm/i915/display/intel_encoder.h

+3 −0
Original line number Diff line number Diff line
@@ -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__ */

drivers/gpu/drm/i915/display/intel_hotplug.c

+0 −2
Original line number Diff line number Diff line
@@ -972,8 +972,6 @@ 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;

drivers/gpu/drm/xe/display/xe_display.c

+6 −0
Original line number Diff line number Diff line
@@ -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)) {
@@ -370,6 +373,7 @@ void xe_display_pm_shutdown(struct xe_device *xe) 


	xe_display_flush_cleanup_work(xe);

	intel_dp_mst_suspend(display);

	intel_encoder_block_all_hpds(display);

	intel_hpd_cancel_work(display);



	if (has_display(xe))
@@ -471,6 +475,8 @@ void xe_display_pm_resume(struct xe_device *xe) 


	intel_hpd_init(display);



	intel_encoder_unblock_all_hpds(display);



	if (has_display(xe)) {

		intel_display_driver_resume(display);

		drm_kms_helper_poll_enable(&xe->drm);