[Intel-gfx] [PATCH 1/1] drm/i915: Do not enable PSR2/selective fetch if there are no planes

[Stanislav Lisovskiy]

We seem to enable PSR2 and selective fetch even if there are no active
planes. That seems to causes FIFO underruns at least for ADLP.
Those are gone if we don't do that. Just adding simple check
in intel_psr2_sel_fetch_config_valid seems to do the trick.

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 7d61c55184e5..03add69cfdca 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -747,6 +747,12 @@ static bool intel_psr2_sel_fetch_config_valid(struct intel_dp *intel_dp,
 		return false;
 	}
 
+	if (hweight32(crtc_state->active_planes) == 0) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "PSR2 sel fetch not enabled, no active_planes\n");
+		return false;
+	}
+
 	/* Wa_14010254185 Wa_14010103792 */
 	if (IS_TGL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_C0)) {
 		drm_dbg_kms(&dev_priv->drm,
-- 
2.24.1.485.gad05a3d8e5