From f482984acb101d351a49ab0ec51c75dbf094a51d Mon Sep 17 00:00:00 2001 From: Manasi Navare Date: Mon, 5 Dec 2016 16:27:36 -0800 Subject: [PATCH] drm/i915: Compute sink's max lane count/link BW at Hotplug Sink's capabilities are advertised through DPCD registers and get updated only on hotplug. So they should be computed only once in the long pulse handler and saved off in intel_dp structure for the use later. For this reason two new fields max_sink_lane_count and max_sink_link_bw are added to intel_dp structure. This also simplifies the fallback link rate/lane count logic to handle link training failure. In that case, the max_sink_link_bw and max_sink_lane_count can be reccomputed to match the fallback values lowering the sink capabilities due to link train failure. Cc: Ville Syrjala Cc: Jani Nikula Cc: Daniel Vetter Signed-off-by: Manasi Navare Reviewed-by: Jani Nikula Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/1480984058-552-3-git-send-email-manasi.d.navare@intel.com --- drivers/gpu/drm/i915/intel_dp.c | 10 ++++++++-- drivers/gpu/drm/i915/intel_drv.h | 4 ++++ 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index db75bb924e48..434dc7d4773a 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -156,7 +156,7 @@ static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp) u8 source_max, sink_max; source_max = intel_dig_port->max_lanes; - sink_max = drm_dp_max_lane_count(intel_dp->dpcd); + sink_max = intel_dp->max_sink_lane_count; return min(source_max, sink_max); } @@ -213,7 +213,7 @@ intel_dp_sink_rates(struct intel_dp *intel_dp, const int **sink_rates) *sink_rates = default_rates; - return (intel_dp_max_link_bw(intel_dp) >> 3) + 1; + return (intel_dp->max_sink_link_bw >> 3) + 1; } static int @@ -4395,6 +4395,12 @@ intel_dp_long_pulse(struct intel_connector *intel_connector) yesno(intel_dp_source_supports_hbr2(intel_dp)), yesno(drm_dp_tps3_supported(intel_dp->dpcd))); + /* Set the max lane count for sink */ + intel_dp->max_sink_lane_count = drm_dp_max_lane_count(intel_dp->dpcd); + + /* Set the max link BW for sink */ + intel_dp->max_sink_link_bw = intel_dp_max_link_bw(intel_dp); + intel_dp_print_rates(intel_dp); intel_dp_read_desc(intel_dp); diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 223d44c4aa93..8e5f2a1e75d8 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -906,6 +906,10 @@ struct intel_dp { /* sink rates as reported by DP_SUPPORTED_LINK_RATES */ uint8_t num_sink_rates; int sink_rates[DP_MAX_SUPPORTED_RATES]; + /* Max lane count for the sink as per DPCD registers */ + uint8_t max_sink_lane_count; + /* Max link BW for the sink as per DPCD registers */ + int max_sink_link_bw; /* sink or branch descriptor */ struct intel_dp_desc desc; struct drm_dp_aux aux; -- 2.30.2