drm/i915/dp: Pass .4 BPP values to {icl,xelpd}_dsc_compute_link_config()

Try to keep the variables in the same domain a bit longer to reduce
juggling between integers and .4 fixed point. Change parameter order to
min, max while at it.

For now, keep the juggling in dsc_compute_compressed_bpp() ensure
min/max will always have 0 fractional part. To be fixed later.

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e72f153fd28755e41ee8c5a7b9e6de257c3b27ac.1738327620.git.jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index e2d252e15ce988e0af27d01da0efc37ae0073bf3..0e941307f399a05a8938819c4e538e04fd6f6973 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2077,8 +2077,8 @@ static int
 icl_dsc_compute_link_config(struct intel_dp *intel_dp,
                            struct intel_crtc_state *pipe_config,
                            const struct link_config_limits *limits,
-                           int dsc_max_bpp,
-                           int dsc_min_bpp,
+                           int min_bpp_x16,
+                           int max_bpp_x16,
                            int pipe_bpp,
                            int timeslots)
 {
@@ -2086,11 +2086,11 @@ icl_dsc_compute_link_config(struct intel_dp *intel_dp,
        int output_bpp = intel_dp_output_bpp(pipe_config->output_format, pipe_bpp);
 
        /* Compressed BPP should be less than the Input DSC bpp */
-       dsc_max_bpp = min(dsc_max_bpp, output_bpp - 1);
+       max_bpp_x16 = min(max_bpp_x16, fxp_q4_from_int(output_bpp - 1));
 
        for (i = ARRAY_SIZE(valid_dsc_bpp) - 1; i >= 0; i--) {
-               if (valid_dsc_bpp[i] < dsc_min_bpp ||
-                   valid_dsc_bpp[i] > dsc_max_bpp)
+               if (valid_dsc_bpp[i] < fxp_q4_to_int(min_bpp_x16) ||
+                   valid_dsc_bpp[i] > fxp_q4_to_int(max_bpp_x16))
                        continue;
 
                ret = dsc_compute_link_config(intel_dp,
@@ -2119,8 +2119,8 @@ xelpd_dsc_compute_link_config(struct intel_dp *intel_dp,
                              const struct intel_connector *connector,
                              struct intel_crtc_state *pipe_config,
                              const struct link_config_limits *limits,
-                             int dsc_max_bpp,
-                             int dsc_min_bpp,
+                             int min_bpp_x16,
+                             int max_bpp_x16,
                              int pipe_bpp,
                              int timeslots)
 {
@@ -2132,10 +2132,9 @@ xelpd_dsc_compute_link_config(struct intel_dp *intel_dp,
        bpp_step_x16 = intel_dp_dsc_bpp_step_x16(connector);
 
        /* Compressed BPP should be less than the Input DSC bpp */
-       dsc_max_bpp = min(dsc_max_bpp << 4, (output_bpp << 4) - bpp_step_x16);
-       dsc_min_bpp = dsc_min_bpp << 4;
+       max_bpp_x16 = min(max_bpp_x16, fxp_q4_from_int(output_bpp) - bpp_step_x16);
 
-       for (bpp_x16 = dsc_max_bpp; bpp_x16 >= dsc_min_bpp; bpp_x16 -= bpp_step_x16) {
+       for (bpp_x16 = max_bpp_x16; bpp_x16 >= min_bpp_x16; bpp_x16 -= bpp_step_x16) {
                if (intel_dp->force_dsc_fractional_bpp_en &&
                    !fxp_q4_to_frac(bpp_x16))
                        continue;
@@ -2168,6 +2167,7 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
        const struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode;
        int dsc_min_bpp;
        int dsc_max_bpp;
+       int min_bpp_x16, max_bpp_x16;
        int dsc_joiner_max_bpp;
        int num_joined_pipes = intel_crtc_num_joined_pipes(pipe_config);
 
@@ -2178,11 +2178,15 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
                                                                num_joined_pipes);
        dsc_max_bpp = min(dsc_joiner_max_bpp, fxp_q4_to_int(limits->link.max_bpp_x16));
 
+       /* FIXME: remove the round trip via integers */
+       min_bpp_x16 = fxp_q4_from_int(dsc_min_bpp);
+       max_bpp_x16 = fxp_q4_from_int(dsc_max_bpp);
+
        if (DISPLAY_VER(display) >= 13)
                return xelpd_dsc_compute_link_config(intel_dp, connector, pipe_config, limits,
-                                                    dsc_max_bpp, dsc_min_bpp, pipe_bpp, timeslots);
+                                                    min_bpp_x16, max_bpp_x16, pipe_bpp, timeslots);
        return icl_dsc_compute_link_config(intel_dp, pipe_config, limits,
-                                          dsc_max_bpp, dsc_min_bpp, pipe_bpp, timeslots);
+                                          min_bpp_x16, max_bpp_x16, pipe_bpp, timeslots);
 }
 
 int intel_dp_dsc_min_src_input_bpc(void)