[PATCH] drm/i915/vdsc: Use the DSC config tables for DSI panels

[Suraj Kandpal <suraj.kandpal@intel.com>]

Some DSI panel vendors end up hardcoding PPS params because of which
it does not listen to the params sent from the source. We use the
default config tables for DSI panels when using DSC 1.1 rather than
calculate our own rc parameters.

--v2
-Use intel_crtc_has_type [Jani]

--v3
-Add Signed-off-by from William too [Ankit]

--v4
-Use a function to check Mipi dsi dsc 1.1 condition [Ankit]
-Add documentation for using this condition [Ankit]
-Rebase

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13719
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: William Tseng <william.tseng@intel.com>
---
 drivers/gpu/drm/i915/display/intel_vdsc.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
index 3ed64c17bdff..2a6706517cfa 100644
--- a/drivers/gpu/drm/i915/display/intel_vdsc.c
+++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
@@ -259,6 +259,13 @@ static int intel_dsc_slice_dimensions_valid(struct intel_crtc_state *pipe_config
 	return 0;
 }
 
+static bool is_mipi_dsi_dsc_1_1(struct drm_dsc_config *vdsc_cfg,
+				struct intel_crtc_state *crtc_state)
+{
+	return vdsc_cfg->dsc_version_minor == 1 &&
+		intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI);
+}
+
 int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
 {
 	struct intel_display *display = to_intel_display(pipe_config);
@@ -317,8 +324,14 @@ int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
 	 * From XE_LPD onwards we supports compression bpps in steps of 1
 	 * upto uncompressed bpp-1, hence add calculations for all the rc
 	 * parameters
+	 * We also don't want to calculate all rc parameters when the panel
+	 * is MIPI DSI and it's using DSC 1.1. The reason being that some
+	 * DSI panels vendors have hardcoded PPS params in the VBT causing
+	 * the parameters sent from the source to be ignore. This causes a
+	 * noise in the display.
 	 */
-	if (DISPLAY_VER(display) >= 13) {
+	if (DISPLAY_VER(display) >= 13 &&
+	    !is_mipi_dsi_dsc_1_1(vdsc_cfg, pipe_config)) {
 		calculate_rc_params(vdsc_cfg);
 	} else {
 		if ((compressed_bpp == 8 ||
-- 
2.34.1