drm/i915: consider the source max DP lane count too

Even if the panel claims it can support 4 lanes, there's the
possibility that the HW can't, so consider this while selecting the
max lane count.

Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Paulo Zanoni 2014-05-06 14:56:50 +03:00 committed by Jani Nikula
parent 2a1235e53b
commit eeb6324dd6

View file

@ -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;