From 191dc43935d1ece82bc6c9653463b3b1cd8198fb Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Thu, 16 Nov 2023 15:18:31 +0200 Subject: drm/dp_mst: Store the MST PBN divider value in fixed point format MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On UHBR links the PBN divider is a fractional number, accordingly store it in fixed point format. For now drm_dp_get_vc_payload_bw() always returns a whole number and all callers will use only the integer part of it which should preserve the current behavior. The next patch will fix drm_dp_get_vc_payload_bw() for UHBR rates returning a fractional number for those (also accounting for the channel coding efficiency correctly). Cc: Lyude Paul Cc: Harry Wentland Cc: Alex Deucher Cc: Wayne Lin Cc: amd-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Reviewed-by: Ville Syrjälä Acked-by: Daniel Vetter Acked-by: Maarten Lankhorst [Rebased changes in dm_helpers_construct_old_payload() on drm-intel-next] Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20231116131841.1588781-2-imre.deak@intel.com --- include/drm/display/drm_dp_mst_helper.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/drm/display') diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h index a4aad6df71f1..9b19d8bd520a 100644 --- a/include/drm/display/drm_dp_mst_helper.h +++ b/include/drm/display/drm_dp_mst_helper.h @@ -25,6 +25,7 @@ #include #include #include +#include #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) #include @@ -617,7 +618,7 @@ struct drm_dp_mst_topology_state { * @pbn_div: The current PBN divisor for this topology. The driver is expected to fill this * out itself. */ - int pbn_div; + fixed20_12 pbn_div; }; #define to_dp_mst_topology_mgr(x) container_of(x, struct drm_dp_mst_topology_mgr, base) @@ -839,8 +840,8 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port); -int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, - int link_rate, int link_lane_count); +fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, + int link_rate, int link_lane_count); int drm_dp_calc_pbn_mode(int clock, int bpp); -- cgit