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* [PATCH] drm/i915/dp: Ignore HPD when in DPLL enable/disable cycle
@ 2026-04-17  8:01 Suraj Kandpal
  2026-04-17  8:27 ` Jani Nikula
                   ` (4 more replies)
  0 siblings, 5 replies; 8+ messages in thread
From: Suraj Kandpal @ 2026-04-17  8:01 UTC (permalink / raw)
  To: intel-xe, intel-gfx, intel-gfx-trybot
  Cc: ankit.k.nautiyal, swati2.sharma, Suraj Kandpal

When we are enable/disable DPLL cycle there are chances the connected
monitors is still sending us HPD signals. This causes us to handle them
which require DPCD read. These sometimes race with the DPLL getting
disabled in between causing AUX failures via Timeout.
Introduce atomic variable link_teardown which is used to track if
we are in DPLL enable/disable cycle. We ignore HPDs during this time.
Re-enable after DPLL is up so that we can avoid populating logs
with expected logs AUX timeout failures.

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c           | 5 +++++
 drivers/gpu/drm/i915/display/intel_display_types.h | 1 +
 drivers/gpu/drm/i915/display/intel_dp.c            | 5 +++++
 3 files changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 178074316a2c..4a523eb56bc4 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2086,8 +2086,12 @@ static struct intel_dpll *hsw_ddi_get_pll(struct intel_encoder *encoder)
 void intel_ddi_enable_clock(struct intel_encoder *encoder,
 			    const struct intel_crtc_state *crtc_state)
 {
+	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
+
 	if (encoder->enable_clock)
 		encoder->enable_clock(encoder, crtc_state);
+
+	atomic_set(&dig_port->link_teardown, 0);
 }
 
 void intel_ddi_disable_clock(struct intel_encoder *encoder)
@@ -3181,6 +3185,7 @@ static void intel_ddi_post_disable_dp(struct intel_atomic_state *state,
 					dig_port->ddi_io_power_domain,
 					wakeref);
 
+	atomic_set(&dig_port->link_teardown, 1);
 	intel_ddi_disable_clock(encoder);
 
 	/* De-select Thunderbolt */
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index c81916761850..f59bbb2fb260 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1985,6 +1985,7 @@ struct intel_digital_port {
 	enum intel_display_power_domain ddi_io_power_domain;
 	struct ref_tracker *ddi_io_wakeref;
 	struct ref_tracker *aux_wakeref;
+	atomic_t link_teardown;
 
 	struct intel_tc_port *tc;
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 35b8fb5740aa..9177fe9b3e84 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -6889,6 +6889,11 @@ intel_dp_hpd_pulse(struct intel_digital_port *dig_port, bool long_hpd)
 	struct intel_dp *intel_dp = &dig_port->dp;
 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
 
+	if (atomic_read(&dig_port->link_teardown)) {
+		drm_dbg_kms("Ignoring HPD since DPLL is getting disabled\n");
+		return IRQ_NONE;
+	}
+
 	if (dig_port->base.type == INTEL_OUTPUT_EDP &&
 	    (long_hpd ||
 	     intel_display_rpm_suspended(display) ||
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2026-04-22  2:47 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-04-17  8:01 [PATCH] drm/i915/dp: Ignore HPD when in DPLL enable/disable cycle Suraj Kandpal
2026-04-17  8:27 ` Jani Nikula
2026-04-17 12:00   ` Jani Nikula
2026-04-17 14:42     ` Kandpal, Suraj
2026-04-17 15:35 ` Ville Syrjälä
2026-04-20 13:21 ` ✓ CI.KUnit: success for " Patchwork
2026-04-22  2:03 ` [PATCH] " kernel test robot
2026-04-22  2:46 ` kernel test robot

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