[PATCH v6 1/1] drm/i915/display: Add no_psr_reason to PSR debugfs

[Michał Grzelak]

There is no reason in debugfs why PSR has been disabled. Add
no_psr_reason field into struct intel_psr. Write the reason,
e.g. PSR setup timing not met, into proper PSR debugfs file.
Clean it when PSR is activated.

Refactor intel_psr_post_plane_update by using no_psr_reason
instead of boolean keep_disabled.

Signed-off-by: Michał Grzelak <michal.grzelak at intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  2 ++
 drivers/gpu/drm/i915/display/intel_psr.c      | 31 ++++++++++---------
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index ce45261c4a8f..bcff1a21f2be 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1685,6 +1685,8 @@ struct intel_psr {
 	bool link_ok;
 
 	u8 active_non_psr_pipes;
+
+	const char *no_psr_reason;
 };
 
 struct intel_dp {
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index ae9053919211..e12f387f1aba 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1590,6 +1590,7 @@ static bool _psr_compute_config(struct intel_dp *intel_dp,
 	if (entry_setup_frames >= 0) {
 		intel_dp->psr.entry_setup_frames = entry_setup_frames;
 	} else {
+		intel_dp->psr.no_psr_reason = "PSR setup timing not met";
 		drm_dbg_kms(display->drm,
 			    "PSR condition failed: PSR setup timing not met\n");
 		return false;
@@ -1819,6 +1820,7 @@ static void intel_psr_activate(struct intel_dp *intel_dp)
 		hsw_activate_psr1(intel_dp);
 
 	intel_dp->psr.active = true;
+	intel_dp->psr.no_psr_reason = NULL;
 }
 
 /*
@@ -2969,28 +2971,29 @@ void intel_psr_post_plane_update(struct intel_atomic_state *state,
 					     crtc_state->uapi.encoder_mask) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 		struct intel_psr *psr = &intel_dp->psr;
-		bool keep_disabled = false;
 
 		mutex_lock(&psr->lock);
 
 		drm_WARN_ON(display->drm,
 			    psr->enabled && !crtc_state->active_planes);
 
-		keep_disabled |= psr->sink_not_reliable;
-		keep_disabled |= !crtc_state->active_planes;
+		if (psr->sink_not_reliable)
+			psr->no_psr_reason = "Sink not reliable";
+		if (!crtc_state->active_planes)
+			psr->no_psr_reason = "All planes inactive";
 
 		/* Display WA #1136: skl, bxt */
-		keep_disabled |= DISPLAY_VER(display) < 11 &&
-			crtc_state->wm_level_disabled;
+		if (DISPLAY_VER(display) < 11 && crtc_state->wm_level_disabled)
+			psr->no_psr_reason = "Workaround for skl, bxt";
 
-		if (!psr->enabled && !keep_disabled)
+		if (!psr->enabled && !psr->no_psr_reason)
 			intel_psr_enable_locked(intel_dp, crtc_state);
 		else if (psr->enabled && !crtc_state->wm_level_disabled)
 			/* Wa_14015648006 */
 			wm_optimization_wa(intel_dp, crtc_state);
 
 		/* Force a PSR exit when enabling CRC to avoid CRC timeouts */
-		if (crtc_state->crc_enabled && psr->enabled)
+		if (psr->enabled && crtc_state->crc_enabled)
 			intel_psr_force_update(intel_dp);
 
 		/*
@@ -3949,12 +3952,7 @@ static void intel_psr_print_mode(struct intel_dp *intel_dp,
 				 struct seq_file *m)
 {
 	struct intel_psr *psr = &intel_dp->psr;
-	const char *status, *mode, *region_et;
-
-	if (psr->enabled)
-		status = " enabled";
-	else
-		status = "disabled";
+	const char *mode, *region_et;
 
 	if (psr->panel_replay_enabled && psr->sel_update_enabled)
 		mode = "Panel Replay Selective Update";
@@ -3972,7 +3970,12 @@ static void intel_psr_print_mode(struct intel_dp *intel_dp,
 	else
 		region_et = "";
 
-	seq_printf(m, "PSR mode: %s%s%s\n", mode, status, region_et);
+	if (psr->enabled) {
+		seq_puts(m, "PSR enabled\n");
+		seq_printf(m, "PSR mode: %s%s\n", mode, region_et);
+	} else {
+		seq_printf(m, "PSR disabled: %s\n", psr->no_psr_reason);
+	}
 }
 
 static int intel_psr_status(struct seq_file *m, struct intel_dp *intel_dp)
-- 
2.45.2