[PATCH 16/16] drm/i915/dsc: Allow DSC only with fractional bpp when forced from debugfs

[Ankit Nautiyal]

From: Swati Sharma <swati2.sharma at intel.com>

If force_dsc_fractional_bpp_en is set through debugfs allow DSC iff
compressed bpp is fractional. Continue if we computed compressed bpp is
computed as integer.

Signed-off-by: Swati Sharma <swati2.sharma at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 8dede5969af5..48ade9077352 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1609,6 +1609,9 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
 	for (compressed_bppx16 = dsc_max_bppx16;
 	     compressed_bppx16 >= dsc_min_bppx16;
 	     compressed_bppx16 -= bppx16_step) {
+		if (intel_dp->force_dsc_fractional_bpp_en &&
+		    (compressed_bppx16 % 16 == 0))
+			continue;
 		ret = dsc_compute_link_config(intel_dp,
 					      pipe_config,
 					      limits,
@@ -1705,6 +1708,9 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 		int forced_bpc = intel_dp->force_dsc_bpc;
 		int forced_bpp = forced_bpc * 3;
 
+		if (intel_dp->force_dsc_fractional_bpp_en)
+			drm_dbg_kms(&dev_priv->drm,
+				    "Forcing DSC fractional bpp\n");
 		if (forced_bpc < 8 ||  /* Min Input BPC for ICL+ is 8 */
 		    forced_bpc > conn_state->max_requested_bpc ||
 		    forced_bpp < limits->min_bpp ||
-- 
2.25.1