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drm/amd/display: Read LTTPR caps first on hotplug 

[WHY]
A new SCR for the DP2.0 spec requires that LTTPR caps be the first thing
read from DPCD upon hotplug.

Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Wesley Chalmers 2021-03-24 13:28:32 -04:00 committed by Alex Deucher
parent f4594cd1fa
commit 0abda67419
1 changed files with 33 additions and 32 deletions
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65
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
View File

@ -3660,38 +3660,6 @@ static bool retrieve_link_cap(struct dc_link *link)
dc_link_aux_try_to_configure_timeout(link->ddc,
LINK_AUX_DEFAULT_LTTPR_TIMEOUT_PERIOD);
status = core_link_read_dpcd(link, DP_SET_POWER,
&dpcd_power_state, sizeof(dpcd_power_state));
/* Delay 1 ms if AUX CH is in power down state. Based on spec
* section 2.3.1.2, if AUX CH may be powered down due to
* write to DPCD 600h = 2. Sink AUX CH is monitoring differential
* signal and may need up to 1 ms before being able to reply.
*/
if (status != DC_OK || dpcd_power_state == DP_SET_POWER_D3)
udelay(1000);
dpcd_set_source_specific_data(link);
/* Sink may need to configure internals based on vendor, so allow some
* time before proceeding with possibly vendor specific transactions
*/
msleep(post_oui_delay);
for (i = 0; i < read_dpcd_retry_cnt; i++) {
status = core_link_read_dpcd(
link,
DP_DPCD_REV,
dpcd_data,
sizeof(dpcd_data));
if (status == DC_OK)
break;
}
if (status != DC_OK) {
dm_error("%s: Read dpcd data failed.\n", __func__);
return false;
}
/* Query BIOS to determine if LTTPR functionality is forced on by system */
if (bios->funcs->get_lttpr_caps) {
enum bp_result bp_query_result;
@ -3778,6 +3746,39 @@ static bool retrieve_link_cap(struct dc_link *link)
dc_link_aux_try_to_configure_timeout(link->ddc, LINK_AUX_DEFAULT_TIMEOUT_PERIOD);
status = core_link_read_dpcd(link, DP_SET_POWER,
&dpcd_power_state, sizeof(dpcd_power_state));
/* Delay 1 ms if AUX CH is in power down state. Based on spec
* section 2.3.1.2, if AUX CH may be powered down due to
* write to DPCD 600h = 2. Sink AUX CH is monitoring differential
* signal and may need up to 1 ms before being able to reply.
*/
if (status != DC_OK || dpcd_power_state == DP_SET_POWER_D3)
udelay(1000);
dpcd_set_source_specific_data(link);
/* Sink may need to configure internals based on vendor, so allow some
* time before proceeding with possibly vendor specific transactions
*/
msleep(post_oui_delay);
for (i = 0; i < read_dpcd_retry_cnt; i++) {
status = core_link_read_dpcd(
link,
DP_DPCD_REV,
dpcd_data,
sizeof(dpcd_data));
if (status == DC_OK)
break;
}
if (status != DC_OK) {
dm_error("%s: Read receiver caps dpcd data failed.\n", __func__);
return false;
}
{
union training_aux_rd_interval aux_rd_interval;