[PATCH 05/22] drm/i915/dp: Limit the output link bpp in DSC mode

[Imre Deak]

Limit the output link bpp in DSC mode to the link_config_limits
link.min_bpp_x16 .. max_bpp_x16 range the same way it's done in non-DSC
mode.  Atm this doesn't make a difference, the link bpp range being
0 .. max pipe bpp, but a follow-up patch will need a way to reduce max
link bpp below its current value.

v2:
- Add to_bpp_int_roundup() instead of open coding it. (Jani)

Cc: Jani Nikula <jani.nikula at linux.intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display_types.h | 5 +++++
 drivers/gpu/drm/i915/display/intel_dp.c            | 4 ++++
 drivers/gpu/drm/i915/display/intel_dp_mst.c        | 3 +++
 3 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index fe8abbacc4fe7..d8d6c1b292d7b 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -2113,6 +2113,11 @@ static inline int to_bpp_int(int bpp_x16)
 	return bpp_x16 >> 4;
 }
 
+static inline int to_bpp_int_roundup(int bpp_x16)
+{
+	return (bpp_x16 + 0xf) >> 4;
+}
+
 static inline int to_bpp_frac_dec(int bpp_x16)
 {
 	return (bpp_x16 & 0xf) * 625;
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 6b287648cafc8..9a0035c3a5664 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1925,6 +1925,7 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
 	dsc_src_min_bpp = dsc_src_min_compressed_bpp();
 	dsc_sink_min_bpp = dsc_sink_min_compressed_bpp(pipe_config);
 	dsc_min_bpp = max(dsc_src_min_bpp, dsc_sink_min_bpp);
+	dsc_min_bpp = max(dsc_min_bpp, to_bpp_int_roundup(limits->link.min_bpp_x16));
 
 	dsc_src_max_bpp = dsc_src_max_compressed_bpp(intel_dp);
 	dsc_sink_max_bpp = dsc_sink_max_compressed_bpp(intel_dp, pipe_config, pipe_bpp / 3);
@@ -1934,6 +1935,7 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
 								adjusted_mode->hdisplay,
 								pipe_config->bigjoiner_pipes);
 	dsc_max_bpp = min(dsc_max_bpp, dsc_joiner_max_bpp);
+	dsc_max_bpp = min(dsc_max_bpp, to_bpp_int(limits->link.max_bpp_x16));
 
 	if (DISPLAY_VER(i915) >= 13)
 		return xelpd_dsc_compute_link_config(intel_dp, pipe_config, limits,
@@ -2079,10 +2081,12 @@ static int intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
 	dsc_src_min_bpp = dsc_src_min_compressed_bpp();
 	dsc_sink_min_bpp = dsc_sink_min_compressed_bpp(pipe_config);
 	dsc_min_bpp = max(dsc_src_min_bpp, dsc_sink_min_bpp);
+	dsc_min_bpp = max(dsc_min_bpp, to_bpp_int_roundup(limits->link.min_bpp_x16));
 
 	dsc_src_max_bpp = dsc_src_max_compressed_bpp(intel_dp);
 	dsc_sink_max_bpp = dsc_sink_max_compressed_bpp(intel_dp, pipe_config, pipe_bpp / 3);
 	dsc_max_bpp = dsc_sink_max_bpp ? min(dsc_sink_max_bpp, dsc_src_max_bpp) : dsc_src_max_bpp;
+	dsc_max_bpp = min(dsc_max_bpp, to_bpp_int(limits->link.max_bpp_x16));
 
 	/* Compressed BPP should be less than the Input DSC bpp */
 	dsc_max_bpp = min(dsc_max_bpp, pipe_bpp - 1);
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 23b3039c15acd..cb34d966e0710 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -233,6 +233,9 @@ static int intel_dp_dsc_mst_compute_link_config(struct intel_encoder *encoder,
 	if (max_bpp > sink_max_bpp)
 		max_bpp = sink_max_bpp;
 
+	min_bpp = max(min_bpp, to_bpp_int_roundup(limits->link.min_bpp_x16));
+	max_bpp = min(max_bpp, to_bpp_int(limits->link.max_bpp_x16));
+
 	slots = intel_dp_mst_find_vcpi_slots_for_bpp(encoder, crtc_state, max_bpp,
 						     min_bpp, limits,
 						     conn_state, 2 * 3, true);
-- 
2.37.2