Commit 903e859b authored by abdoulaye berthe's avatar abdoulaye berthe Committed by Alex Deucher
Browse files

drm/amd/display: check for dp rev before reading lttpr regs 



[Why]
LTTPR was introduced after DP1.2. Reading LTTPR registers 0xFXXXX
on some DP 1.2 display is causing an unexpected behavior.

[How]
Make sure that we don't read any lttpr registers on 1.2 displays.

Signed-off-by: default avatarabdoulaye berthe <abdoulaye.berthe@amd.com>
Reviewed-by: default avatarAric Cyr <Aric.Cyr@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 8e5100a5

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

+3 −2
Original line number Diff line number Diff line
@@ -2759,9 +2759,10 @@ static bool retrieve_link_cap(struct dc_link *link) 
	/* Set default timeout to 3.2ms and read LTTPR capabilities */

	bool ext_timeout_support = link->dc->caps.extended_aux_timeout_support &&

			!link->dc->config.disable_extended_timeout_support;

	link->is_lttpr_mode_transparent = true;



	if (ext_timeout_support) {

		status = dc_link_aux_configure_timeout(link->ddc, LINK_AUX_DEFAULT_EXTENDED_TIMEOUT_PERIOD);

		link->is_lttpr_mode_transparent = true;

	}



	memset(dpcd_data, '\0', sizeof(dpcd_data));
@@ -2796,7 +2797,7 @@ static bool retrieve_link_cap(struct dc_link *link) 
		return false;

	}



	if (ext_timeout_support) {

	if (ext_timeout_support && link->dpcd_caps.dpcd_rev.raw >= 0x14) {

		status = core_link_read_dpcd(

				link,

				DP_PHY_REPEATER_CNT,

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