Commit 259e2e0a authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915/dp: Account for tunnel BW limit in intel_dp_max_link_data_rate() 



Take any link BW limitation into account in
intel_dp_max_link_data_rate(). Such a limitation can be due to multiple
displays on (Thunderbolt) links with DP tunnels sharing the link BW.

Reviewed-by: default avatarUma Shankar <uma.shankar@intel.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240220211841.448846-15-imre.deak@intel.com
parent 39818c06

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

+28 −4
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ 
#include "intel_dp_hdcp.h"

#include "intel_dp_link_training.h"

#include "intel_dp_mst.h"

#include "intel_dp_tunnel.h"

#include "intel_dpio_phy.h"

#include "intel_dpll.h"

#include "intel_fifo_underrun.h"
@@ -152,6 +153,22 @@ int intel_dp_link_symbol_clock(int rate) 
	return DIV_ROUND_CLOSEST(rate * 10, intel_dp_link_symbol_size(rate));

}



static int max_dprx_rate(struct intel_dp *intel_dp)

{

	if (intel_dp_tunnel_bw_alloc_is_enabled(intel_dp))

		return drm_dp_tunnel_max_dprx_rate(intel_dp->tunnel);



	return drm_dp_bw_code_to_link_rate(intel_dp->dpcd[DP_MAX_LINK_RATE]);

}



static int max_dprx_lane_count(struct intel_dp *intel_dp)

{

	if (intel_dp_tunnel_bw_alloc_is_enabled(intel_dp))

		return drm_dp_tunnel_max_dprx_lane_count(intel_dp->tunnel);



	return drm_dp_max_lane_count(intel_dp->dpcd);

}



static void intel_dp_set_default_sink_rates(struct intel_dp *intel_dp)

{

	intel_dp->sink_rates[0] = 162000;
@@ -180,7 +197,7 @@ static void intel_dp_set_dpcd_sink_rates(struct intel_dp *intel_dp) 
	/*

	 * Sink rates for 8b/10b.

	 */

	max_rate = drm_dp_bw_code_to_link_rate(intel_dp->dpcd[DP_MAX_LINK_RATE]);

	max_rate = max_dprx_rate(intel_dp);

	max_lttpr_rate = drm_dp_lttpr_max_link_rate(intel_dp->lttpr_common_caps);

	if (max_lttpr_rate)

		max_rate = min(max_rate, max_lttpr_rate);
@@ -259,7 +276,7 @@ static void intel_dp_set_max_sink_lane_count(struct intel_dp *intel_dp) 
	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);

	struct intel_encoder *encoder = &intel_dig_port->base;



	intel_dp->max_sink_lane_count = drm_dp_max_lane_count(intel_dp->dpcd);

	intel_dp->max_sink_lane_count = max_dprx_lane_count(intel_dp);



	switch (intel_dp->max_sink_lane_count) {

	case 1:
@@ -389,14 +406,21 @@ int intel_dp_effective_data_rate(int pixel_clock, int bpp_x16, 
 * @max_dprx_rate: Maximum data rate of the DPRX

 * @max_dprx_lanes: Maximum lane count of the DPRX

 *

 * Calculate the maximum data rate for the provided link parameters.

 * Calculate the maximum data rate for the provided link parameters taking into

 * account any BW limitations by a DP tunnel attached to @intel_dp.

 *

 * Returns the maximum data rate in kBps units.

 */

int intel_dp_max_link_data_rate(struct intel_dp *intel_dp,

				int max_dprx_rate, int max_dprx_lanes)

{

	return drm_dp_max_dprx_data_rate(max_dprx_rate, max_dprx_lanes);

	int max_rate = drm_dp_max_dprx_data_rate(max_dprx_rate, max_dprx_lanes);



	if (intel_dp_tunnel_bw_alloc_is_enabled(intel_dp))

		max_rate = min(max_rate,

			       drm_dp_tunnel_available_bw(intel_dp->tunnel));



	return max_rate;

}



bool intel_dp_can_bigjoiner(struct intel_dp *intel_dp)