[PATCH v6 6/8] 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.

v1: Initial version.
v2: Add centralized alpm error handling. [Jouni]
v3: Improve debug print. [Jouni]

Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
---
 drivers/gpu/drm/i915/display/intel_alpm.c | 27 +++++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_alpm.h |  1 +
 drivers/gpu/drm/i915/display/intel_dp.c   |  3 +++
 drivers/gpu/drm/i915/display/intel_psr.c  | 18 ++-------------
 4 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index dc24772743b8..562f7269a583 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.c
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c
@@ -496,4 +496,31 @@ void intel_alpm_disable(struct intel_dp *intel_dp)
 	intel_de_rmw(display,
 		     PORT_ALPM_CTL(cpu_transcoder),
 		     PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
+
+	drm_dbg_kms(display->drm, "Disabling ALPM\n");
+}
+
+bool intel_alpm_get_error(struct intel_dp *intel_dp)
+{
+	struct intel_display *display = to_intel_display(intel_dp);
+	struct drm_dp_aux *aux = &intel_dp->aux;
+	u8 val;
+	int r;
+
+	r = drm_dp_dpcd_readb(aux, DP_RECEIVER_ALPM_STATUS, &val);
+	if (r != 1) {
+		drm_err(display->drm, "Error reading ALPM status\n");
+		return true;
+	}
+
+	if (val & DP_ALPM_LOCK_TIMEOUT_ERROR) {
+		drm_dbg_kms(display->drm,
+			    "ALPM lock timeout error\n");
+
+		/* Clearing error */
+		drm_dp_dpcd_writeb(aux, DP_RECEIVER_ALPM_STATUS, val);
+		return true;
+	}
+
+	return false;
 }
diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h b/drivers/gpu/drm/i915/display/intel_alpm.h
index 91f51fb24f98..2f1fb82c0aac 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_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_disable(struct intel_dp *intel_dp);
+bool intel_alpm_get_error(struct intel_dp *intel_dp);
 #endif
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index a236b5fc7a3d..3f0fa2238afa 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5358,6 +5358,9 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
 
 	intel_psr_short_pulse(intel_dp);
 
+	if (intel_alpm_get_error(intel_dp))
+		intel_alpm_disable(intel_dp);
+
 	if (intel_dp_test_short_pulse(intel_dp))
 		reprobe_needed = true;
 
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 1d202f2eb356..09d440084671 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -3405,29 +3405,15 @@ static int psr_get_status_and_error_status(struct intel_dp *intel_dp,
 
 static void psr_alpm_check(struct intel_dp *intel_dp)
 {
-	struct intel_display *display = to_intel_display(intel_dp);
-	struct drm_dp_aux *aux = &intel_dp->aux;
 	struct intel_psr *psr = &intel_dp->psr;
-	u8 val;
-	int r;
 
 	if (!psr->sel_update_enabled)
 		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) {
+	if (intel_alpm_get_error(intel_dp)) {
 		intel_psr_disable_locked(intel_dp);
 		psr->sink_not_reliable = true;
-		drm_dbg_kms(display->drm,
-			    "ALPM lock timeout error, disabling PSR\n");
-
-		/* Clearing error */
-		drm_dp_dpcd_writeb(aux, DP_RECEIVER_ALPM_STATUS, val);
+		intel_alpm_disable(intel_dp);
 	}
 }
 
-- 
2.29.0