diff options
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp.c | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 6bcaba434788..ea557af82662 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -191,6 +191,29 @@ static void intel_dp_set_default_sink_rates(struct intel_dp *intel_dp) intel_dp->num_sink_rates = 1; } +static bool dprx_supports_128b132b(struct intel_dp *intel_dp) +{ + if (intel_dp_tunnel_bw_alloc_is_enabled(intel_dp)) + return drm_dp_tunnel_128b132b_supported(intel_dp->tunnel); + else + return drm_dp_128b132b_supported(intel_dp->dpcd); +} + +static u8 dprx_128b132b_link_rates(struct intel_dp *intel_dp, u8 no_bwa_rates) +{ + u8 ret; + + if (!intel_dp_tunnel_bw_alloc_is_enabled(intel_dp)) + return no_bwa_rates; + + ret = drm_dp_tunnel_128b132b_dprx_rates(intel_dp->tunnel); + static_assert(DP_TUNNELING_10GBPS_PER_LANE_SUPPORT == DP_UHBR10 && + DP_TUNNELING_13_5GBPS_PER_LANE_SUPPORT == DP_UHBR13_5 && + DP_TUNNELING_20GBPS_PER_LANE_SUPPORT == DP_UHBR20); + + return ret; +} + /* update sink rates from dpcd */ static void intel_dp_set_dpcd_sink_rates(struct intel_dp *intel_dp) { @@ -199,6 +222,7 @@ static void intel_dp_set_dpcd_sink_rates(struct intel_dp *intel_dp) }; int i, max_rate; int max_lttpr_rate; + u8 uhbr_rates = 0; if (drm_dp_has_quirk(&intel_dp->desc, DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS)) { /* Needed, e.g., for Apple MBP 2017, 15 inch eDP Retina panel */ @@ -225,16 +249,19 @@ static void intel_dp_set_dpcd_sink_rates(struct intel_dp *intel_dp) } /* + * The following register must be read unconditionally for the later + * DP tunnel 128b132b detection to work, see DP Standard v2.1 5.14.3 . + */ + drm_dp_dpcd_read_byte(&intel_dp->aux, DP_128B132B_SUPPORTED_LINK_RATES, &uhbr_rates); + + /* * Sink rates for 128b/132b. If set, sink should support all 8b/10b * rates and 10 Gbps. */ - if (drm_dp_128b132b_supported(intel_dp->dpcd)) { - u8 uhbr_rates = 0; - + if (dprx_supports_128b132b(intel_dp)) { BUILD_BUG_ON(ARRAY_SIZE(intel_dp->sink_rates) < ARRAY_SIZE(dp_rates) + 3); - drm_dp_dpcd_readb(&intel_dp->aux, - DP_128B132B_SUPPORTED_LINK_RATES, &uhbr_rates); + uhbr_rates = dprx_128b132b_link_rates(intel_dp, uhbr_rates); if (drm_dp_lttpr_count(intel_dp->lttpr_common_caps)) { /* We have a repeater */ |