drm/i915/dp_mst: Track min link BPP as x16 fixed-point during mode validation

Track the minimum link BPP as an x16 fixed-point value and, for
clarity, rename the variable storing it to min_link_bpp_x16.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260216070421.714884-4-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 29713075e4135da9ea76cfdf9d64293194b69d1d..7ca2e2245fc70b95d497a5fc5c7a0ce875b46265 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -1463,10 +1463,10 @@ mst_connector_mode_valid_ctx(struct drm_connector *_connector,
        struct intel_dp *intel_dp = connector->mst.dp;
        struct drm_dp_mst_topology_mgr *mgr = &intel_dp->mst.mgr;
        struct drm_dp_mst_port *port = connector->mst.port;
-       const int min_bpp = 18;
        int max_rate, mode_rate, max_lanes, max_link_clock;
        unsigned long bw_overhead_flags =
                DRM_DP_BW_OVERHEAD_MST | DRM_DP_BW_OVERHEAD_SSC_REF_CLK;
+       int min_link_bpp_x16 = fxp_q4_from_int(18);
        int ret;
        bool dsc = false;
        int target_clock = mode->clock;
@@ -1498,7 +1498,7 @@ mst_connector_mode_valid_ctx(struct drm_connector *_connector,
                                               max_link_clock, max_lanes);
        mode_rate = intel_dp_link_required(max_link_clock, max_lanes,
                                           mode->clock, mode->hdisplay,
-                                          fxp_q4_from_int(min_bpp),
+                                          min_link_bpp_x16,
                                           bw_overhead_flags);
 
        /*
@@ -1518,7 +1518,7 @@ mst_connector_mode_valid_ctx(struct drm_connector *_connector,
                return ret;
 
        if (mode_rate > max_rate ||
-           drm_dp_calc_pbn_mode(mode->clock, min_bpp << 4) > port->full_pbn) {
+           drm_dp_calc_pbn_mode(mode->clock, min_link_bpp_x16) > port->full_pbn) {
                *status = MODE_CLOCK_HIGH;
                return 0;
        }