Commit 41283596 authored by Nikola Cornij's avatar Nikola Cornij Committed by Lyude Paul
Browse files

drm/i915: Use the correct max source link rate for MST 



[why]
Previously used value was not safe to provide the correct value, i.e. it
could be 0 if not not configured, leading to no MST on this platform.

[how]
Do not use the value from BIOS, but from the structure populated at
encoder initialization time.

Fixes: 98025a62 ("drm/dp_mst: Use Extended Base Receiver Capability DPCD space")
Signed-off-by: default avatarNikola Cornij <nikola.cornij@amd.com>
Reviewed-by: default avatarLyude Paul <lyude@redhat.com>
Acked-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
[fixed open coded drm_dp_link_rate_to_bw_code()]
Signed-off-by: default avatarLyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210430214531.24565-2-nikola.cornij@amd.com
parent 70e12560

drivers/gpu/drm/i915/display/intel_dp_mst.c

+4 −3
Original line number Diff line number Diff line
@@ -942,7 +942,8 @@ intel_dp_mst_encoder_init(struct intel_digital_port *dig_port, int conn_base_id) 
	struct intel_dp *intel_dp = &dig_port->dp;

	enum port port = dig_port->base.port;

	int ret;

	int bios_max_link_rate;

	int max_source_rate =

		intel_dp->source_rates[intel_dp->num_source_rates - 1];



	if (!HAS_DP_MST(i915) || intel_dp_is_edp(intel_dp))

		return 0;
@@ -957,11 +958,11 @@ intel_dp_mst_encoder_init(struct intel_digital_port *dig_port, int conn_base_id) 


	/* create encoders */

	intel_dp_create_fake_mst_encoders(dig_port);

	bios_max_link_rate = intel_bios_dp_max_link_rate(&dig_port->base);

	ret = drm_dp_mst_topology_mgr_init(&intel_dp->mst_mgr, &i915->drm,

					   &intel_dp->aux, 16, 3,

					   (u8)dig_port->max_lanes,

					   (u8)(bios_max_link_rate / 27000), conn_base_id);

					   drm_dp_link_rate_to_bw_code(max_source_rate),

					   conn_base_id);

	if (ret)

		return ret;