Enable SDP error detection configuration, this will set CRC16 in
128b/132b link layer.
For DISPLAY13 a hardware bit31 in register VIDEO_DIP_CTL is added to
enable/disable SDP CRC applicable for DP2.0 only, but the default value
of this bit will enable CRC16 in 128b/132b hence skipping this write.
Corrective actions on SDP corruption is yet to be defined.
Signed-off-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_dp.c | 13 +++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 1 +
2 files changed, 14 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 30c55f980014..6096825a27ca 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -133,6 +133,7 @@ static void intel_dp_set_default_sink_rates(struct intel_dp *intel_dp)
/* update sink rates from dpcd */
static void intel_dp_set_dpcd_sink_rates(struct intel_dp *intel_dp)
{
+ struct drm_i915_private *i915 = dp_to_i915(intel_dp);
static const int dp_rates[] = {
162000, 270000, 540000, 810000
};
@@ -196,6 +197,18 @@ static void intel_dp_set_dpcd_sink_rates(struct intel_dp *intel_dp)
intel_dp->sink_rates[i++] = 1350000;
if (uhbr_rates & DP_UHBR20)
intel_dp->sink_rates[i++] = 2000000;
+
+ /* DP v2.0 SCR on SDP CRC16 for 128b/132b Link Layer */
+ if (HAS_DP20(i915))
+ drm_dp_dpcd_writeb(&intel_dp->aux,
+ DP_SDP_ERROR_DETECTION,
+ DP_SDP_CRC16_128B132B_EN);
+ /*
+ * VIDEO_DIP_CTL register bit 31 should be set to '0' to not
+ * disable SDP CRC. This is applicable for DISPLAY 13. Default
+ * value of bit 31 is '0' hence discarging the write
+ */
+ /* TODO: Corrective actions on SDP corruption yet to be defined */
}
intel_dp->num_sink_rates = i;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 8b2cf980f323..77e265f59978 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2674,6 +2674,7 @@
#define VIDEO_DIP_FREQ_2VSYNC (2 << 16)
#define VIDEO_DIP_FREQ_MASK (3 << 16)
/* HSW and later: */
+#define VIDEO_DISABLE_SDP_CRC (1 << 31)
#define VIDEO_DIP_ENABLE_DRM_GLK (1 << 28)
#define PSR_VSC_BIT_7_SET (1 << 27)
#define VSC_SELECT_MASK (0x3 << 25)
--
2.25.1
