diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 5ca68aa9f237..115662c2f048 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -121,6 +121,22 @@ intel_dp_max_link_bw(struct intel_dp *intel_dp) return max_link_bw; } +static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp) +{ + struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp); + struct drm_device *dev = intel_dig_port->base.base.dev; + u8 source_max, sink_max; + + source_max = 4; + if (HAS_DDI(dev) && intel_dig_port->port == PORT_A && + (intel_dig_port->saved_port_bits & DDI_A_4_LANES) == 0) + source_max = 2; + + sink_max = drm_dp_max_lane_count(intel_dp->dpcd); + + return min(source_max, sink_max); +} + /* * The units on the numbers in the next two are... bizarre. Examples will * make it clearer; this one parallels an example in the eDP spec. @@ -171,7 +187,7 @@ intel_dp_mode_valid(struct drm_connector *connector, } max_link_clock = drm_dp_bw_code_to_link_rate(intel_dp_max_link_bw(intel_dp)); - max_lanes = drm_dp_max_lane_count(intel_dp->dpcd); + max_lanes = intel_dp_max_lane_count(intel_dp); max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); mode_rate = intel_dp_link_required(target_clock, 18); @@ -751,7 +767,7 @@ intel_dp_compute_config(struct intel_encoder *encoder, struct intel_crtc *intel_crtc = encoder->new_crtc; struct intel_connector *intel_connector = intel_dp->attached_connector; int lane_count, clock; - int max_lane_count = drm_dp_max_lane_count(intel_dp->dpcd); + int max_lane_count = intel_dp_max_lane_count(intel_dp); /* Conveniently, the link BW constants become indices with a shift...*/ int max_clock = intel_dp_max_link_bw(intel_dp) >> 3; int bpp, mode_rate; |