[PATCH 17/26] drm/i915/dp: Make sure the DSC PPS SDP is disabled whenever DSC is disabled

[Imre Deak]

Atm the DSC PPS SDP will stay enabled after enabling and disabling DSC.
This leaves an output blank after switching off DSC on it. Make sure the
SDP is disabled for an uncompressed output.

Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/display/intel_vdsc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
index b24601d0b2c50..30b4145959a11 100644
--- a/drivers/gpu/drm/i915/display/intel_vdsc.c
+++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
@@ -724,9 +724,15 @@ void intel_dsc_dsi_pps_write(struct intel_encoder *encoder,
 void intel_dsc_dp_pps_write(struct intel_encoder *encoder,
 			    const struct intel_crtc_state *crtc_state)
 {
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
 	const struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config;
 	struct drm_dsc_pps_infoframe dp_dsc_pps_sdp;
+	i915_reg_t reg = HSW_TVIDEO_DIP_CTL(crtc_state->cpu_transcoder);
+	u32 val = intel_de_read(dev_priv, reg) & ~VDIP_ENABLE_PPS;
+
+	intel_de_write(dev_priv, reg, val);
+	intel_de_posting_read(dev_priv, reg);
 
 	if (!crtc_state->dsc.compression_enable)
 		return;
-- 
2.37.2