Commit a504ad26 authored by Hugo Hu's avatar Hugo Hu Committed by Alex Deucher
Browse files

drm/amd/display: Handle branch device with DFP count = 0 case. 



[Why]
When you have a SST branch device the driver, Even no sink device connected,
it also send HPD with a valid EDID. Driver will config it to DP sink.
Therefore, there're two displays in display setting.

DPCD 0x05, DFP_PRESENT = 1 (branch device),
DFP_TYPE = 00 (Display Port)

[How]
Driver determine DPCD 0x05 DFP_PRESENT = 1(branch) as an active dongle
And check DFP count.

Signed-off-by: default avatarHugo Hu <hugo.hu@amd.com>
Reviewed-by: default avatarHugo Hu <Hugo.Hu@amd.com>
Acked-by: default avatarBhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 3ae42acd

drivers/gpu/drm/amd/display/dc/core/dc_link.c

+2 −3
Original line number Diff line number Diff line
@@ -720,9 +720,8 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason) 
					same_dpcd = false;

			}

			/* Active dongle plug in without display or downstream unplug*/

			if (link->type == dc_connection_active_dongle

					&& link->dpcd_caps.sink_count.

					bits.SINK_COUNT == 0) {

			if (link->type == dc_connection_active_dongle &&

				link->dpcd_caps.sink_count.bits.SINK_COUNT == 0) {

				if (prev_sink != NULL) {

					/* Downstream unplug */

					dc_sink_release(prev_sink);

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

+4 −5
Original line number Diff line number Diff line
@@ -2226,11 +2226,7 @@ bool is_mst_supported(struct dc_link *link) 


bool is_dp_active_dongle(const struct dc_link *link)

{

	enum display_dongle_type dongle_type = link->dpcd_caps.dongle_type;



	return (dongle_type == DISPLAY_DONGLE_DP_VGA_CONVERTER) ||

			(dongle_type == DISPLAY_DONGLE_DP_DVI_CONVERTER) ||

			(dongle_type == DISPLAY_DONGLE_DP_HDMI_CONVERTER);

	return link->dpcd_caps.is_branch_dev;

}



static int translate_dpcd_max_bpc(enum dpcd_downstream_port_max_bpc bpc)
@@ -2264,6 +2260,9 @@ static void get_active_converter_info( 
		return;

	}



	/* DPCD 0x5 bit 0 = 1, it indicate it's branch device */

	link->dpcd_caps.is_branch_dev = ds_port.fields.PORT_PRESENT;



	switch (ds_port.fields.PORT_TYPE) {

	case DOWNSTREAM_VGA:

		link->dpcd_caps.dongle_type = DISPLAY_DONGLE_DP_VGA_CONVERTER;

drivers/gpu/drm/amd/display/dc/dc.h

+2 −0
Original line number Diff line number Diff line
@@ -689,6 +689,8 @@ struct dpcd_caps { 


	/* dongle type (DP converter, CV smart dongle) */

	enum display_dongle_type dongle_type;

	/* branch device or sink device */

	bool is_branch_dev;

	/* Dongle's downstream count. */

	union sink_count sink_count;

	/* If dongle_type == DISPLAY_DONGLE_DP_HDMI_CONVERTER,

CRA Git | Maintained and supported by SUSTech CRA and CCSE