[Intel-gfx] [PATCH v4 14/25] drm/i915/dp: Do not enable PSR2 if DSC is enabled

[Manasi Navare]

If a eDP panel supports both PSR2 and VDSC, our HW cannot
support both at a time. Give priority to PSR2 if a requested
resolution can be supported without compression else enable
VDSC and keep PSR2 disabled.

v2:
* Add warning for DSC and PSR2 enabled together (DK)

Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_psr.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index b6838b525502..13cacf8a25e3 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -71,6 +71,10 @@ static bool psr_global_enabled(u32 debug)
 static bool intel_psr2_enabled(struct drm_i915_private *dev_priv,
 			       const struct intel_crtc_state *crtc_state)
 {
+	/* Cannot enable DSC and PSR2 simultaneously */
+	WARN_ON(crtc_state->dsc_params.compression_enable &&
+		crtc_state->has_psr2);
+
 	switch (dev_priv->psr.debug & I915_PSR_DEBUG_MODE_MASK) {
 	case I915_PSR_DEBUG_FORCE_PSR1:
 		return false;
@@ -458,6 +462,16 @@ static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 	if (!dev_priv->psr.sink_psr2_support)
 		return false;
 
+	/*
+	 * DSC and PSR2 cannot be enabled simultaneously. If a requested
+	 * resolution requires DSC to be enabled, priority is given to DSC
+	 * over PSR2.
+	 */
+	if (crtc_state->dsc_params.compression_enable) {
+		DRM_DEBUG_KMS("PSR2 cannot be enabled since DSC is enabled\n");
+		return false;
+	}
+
 	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) {
 		psr_max_h = 4096;
 		psr_max_v = 2304;
-- 
2.18.0