diff options
| -rw-r--r-- | drivers/gpu/drm/display/drm_dp_mst_topology.c | 10 | ||||
| -rw-r--r-- | include/drm/display/drm_dp_helper.h | 13 |
2 files changed, 20 insertions, 3 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index 7efbd8ef664f..ab39c7ad9b89 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -3585,14 +3585,18 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, int link_rate, int link_lane_count) { + int ch_coding_efficiency = + drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(link_rate)); fixed20_12 ret; if (link_rate == 0 || link_lane_count == 0) drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n", link_rate, link_lane_count); - /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ - ret.full = dfixed_const(link_rate * link_lane_count / 54000); + /* See DP v2.0 2.6.4.2, 2.7.6.3 VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ + ret.full = DIV_ROUND_DOWN_ULL(mul_u32_u32(link_rate * link_lane_count, + ch_coding_efficiency), + (1000000ULL * 8 * 5400) >> 12); return ret; } @@ -4342,7 +4346,7 @@ int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state, } } - req_slots = DIV_ROUND_UP(pbn, dfixed_trunc(topology_state->pbn_div)); + req_slots = DIV_ROUND_UP(dfixed_const(pbn), topology_state->pbn_div.full); drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n", port->connector->base.id, port->connector->name, diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index 194715083399..b88cc53425e0 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -252,6 +252,19 @@ drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]) return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP); } +/** + * drm_dp_is_uhbr_rate - Determine if a link rate is UHBR + * @link_rate: link rate in 10kbits/s units + * + * Determine if the provided link rate is an UHBR rate. + * + * Returns: %True if @link_rate is an UHBR rate. + */ +static inline bool drm_dp_is_uhbr_rate(int link_rate) +{ + return link_rate >= 1000000; +} + /* * DisplayPort AUX channel */ |