[PATCH v2 08/11] drm/i915/psr: Check if source supports sink specific SU granularity

[José Roberto de Souza]

According to eDP spec, sink can required specific selective update
granularity that source must comply.
Here caching the value if required and checking if source supports
it.

Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h  |  1 +
 drivers/gpu/drm/i915/intel_psr.c | 21 ++++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 43ac6873a2bb..0727d8051dd3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -507,6 +507,7 @@ struct i915_psr {
 	ktime_t last_exit;
 	bool sink_not_reliable;
 	bool irq_aux_error;
+	u16 su_x_granularity;
 };
 
 enum intel_pch {
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 282ff1bc68a7..f9eccaac850a 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -261,6 +261,23 @@ static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp)
 	return val;
 }
 
+static u16 intel_dp_get_su_x_granulartiy(struct intel_dp *intel_dp)
+{
+	u16 val;
+	ssize_t r;
+
+	if (!(intel_dp->psr_dpcd[1] & DP_PSR2_SU_GRANULARITY_REQUIRED)) {
+		/* Returning the default X granularity */
+		return 4;
+	}
+
+	r = drm_dp_dpcd_read(&intel_dp->aux, DP_PSR2_SU_X_GRANULARITY, &val, 2);
+	if (r != 2)
+		DRM_WARN("Unable to read DP_PSR2_SU_X_GRANULARITY\n");
+
+	return val;
+}
+
 void intel_psr_init_dpcd(struct intel_dp *intel_dp)
 {
 	struct drm_i915_private *dev_priv =
@@ -315,6 +332,8 @@ void intel_psr_init_dpcd(struct intel_dp *intel_dp)
 		if (dev_priv->psr.sink_psr2_support) {
 			dev_priv->psr.colorimetry_support =
 				intel_dp_get_colorimetry_status(intel_dp);
+			dev_priv->psr.su_x_granularity =
+				intel_dp_get_su_x_granulartiy(intel_dp);
 		}
 	}
 }
@@ -546,7 +565,7 @@ static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 	 * at each 4 lines with height of 4 lines, what eDP states
 	 * that sink should support.
 	 */
-	if (crtc_hdisplay % 4) {
+	if (crtc_hdisplay % dev_priv->psr.su_x_granularity) {
 		DRM_DEBUG_KMS("PSR2 not enabled, default SU granularity not match\n");
 		return false;
 	}
-- 
2.19.2