[PATCH v3 5/6] drm/i915/lobf: Check for sink error and disable LOBF

[Animesh Manna <animesh.manna@xxxxxxxxx>]

Disable LOBF/ALPM for any erroneous condition from sink side.

Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
---
 drivers/gpu/drm/i915/display/intel_alpm.c     | 38 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_alpm.h     |  1 +
 .../drm/i915/display/intel_display_types.h    |  1 +
 drivers/gpu/drm/i915/display/intel_dp.c       |  2 +
 4 files changed, 42 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index 1cc0e5ed3f74..ab98b48ec47e 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.c
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c
@@ -388,6 +388,7 @@ void intel_alpm_configure(struct intel_dp *intel_dp,
 			  const struct intel_crtc_state *crtc_state)
 {
 	lnl_alpm_configure(intel_dp, crtc_state);
+	intel_dp->alpm_parameters.transcoder = crtc_state->cpu_transcoder;
 }
 
 void intel_alpm_post_plane_update(struct intel_atomic_state *state,
@@ -511,3 +512,40 @@ void intel_alpm_lobf_debugfs_add(struct intel_connector *connector)
 	debugfs_create_file("i915_edp_lobf_info", 0444, root,
 			    connector, &i915_edp_lobf_info_fops);
 }
+
+void intel_alpm_short_pulse(struct intel_dp *intel_dp)
+{
+	struct intel_display *display = to_intel_display(intel_dp);
+	struct drm_dp_aux *aux = &intel_dp->aux;
+	enum transcoder cpu_transcoder = intel_dp->alpm_parameters.transcoder;
+	u8 val;
+	int r;
+
+	if (DISPLAY_VER(display) < 20)
+		return;
+
+	if (!(intel_de_read(display, ALPM_CTL(display, cpu_transcoder)) & ALPM_CTL_LOBF_ENABLE))
+		return;
+
+	r = drm_dp_dpcd_readb(aux, DP_RECEIVER_ALPM_STATUS, &val);
+	if (r != 1) {
+		drm_err(display->drm, "Error reading ALPM status\n");
+		return;
+	}
+
+	if (val & DP_ALPM_LOCK_TIMEOUT_ERROR) {
+		intel_de_rmw(display, ALPM_CTL(display, cpu_transcoder),
+			     ALPM_CTL_ALPM_ENABLE | ALPM_CTL_LOBF_ENABLE |
+			     ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
+
+		intel_de_rmw(display,
+			     PORT_ALPM_CTL(cpu_transcoder),
+			     PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
+
+		drm_dbg_kms(display->drm,
+			    "ALPM lock timeout error, disabling LOBF\n");
+
+		/* Clearing error */
+		drm_dp_dpcd_writeb(aux, DP_RECEIVER_ALPM_STATUS, val);
+	}
+}
diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h b/drivers/gpu/drm/i915/display/intel_alpm.h
index 485e511629fb..96d4c903f3ea 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.h
+++ b/drivers/gpu/drm/i915/display/intel_alpm.h
@@ -29,4 +29,5 @@ void intel_alpm_post_plane_update(struct intel_atomic_state *state,
 void intel_alpm_lobf_debugfs_add(struct intel_connector *connector);
 bool intel_alpm_aux_wake_supported(struct intel_dp *intel_dp);
 bool intel_alpm_aux_less_wake_supported(struct intel_dp *intel_dp);
+void intel_alpm_short_pulse(struct intel_dp *intel_dp);
 #endif
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 37f061acb204..636af4c4e94d 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1806,6 +1806,7 @@ struct intel_dp {
 #define I915_LOBF_DEBUG_DISABLE			0x01
 #define I915_LOBF_DEBUG_FORCE_EN		0x02
 		bool lobf_debug;
+		enum transcoder transcoder;
 	} alpm_parameters;
 
 	u8 alpm_dpcd;
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 0d74adae2ec9..40f2760d8aaa 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5363,6 +5363,8 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
 
 	intel_psr_short_pulse(intel_dp);
 
+	intel_alpm_short_pulse(intel_dp);
+
 	if (intel_dp_test_short_pulse(intel_dp))
 		reprobe_needed = true;
 
-- 
2.29.0