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authorEric Yang <Eric.Yang2@amd.com>2018-11-23 05:55:20 -0500
committerAlex Deucher <alexander.deucher@amd.com>2018-12-18 18:25:12 -0500
commit80adaebd2d411b7d6872a097634848a71eb13d20 (patch)
treefdfe85d10de3ce8cced66ff3d8977d160445b72f /drivers/gpu/drm
parent0a6414e75d231ee1bb7ffb2f5eb246b682a884cd (diff)
drm/amd/display: Don't skip link training for empty dongle
[Why] Skipping initial link training will result in no verified link cap for mode enumeration. Some versions of the BIOS seem to have PHY programming sequence issue as well if initial link training is skipped, resulting in a softlock in BIOS command table. [How] Identify the empty dongle hotplug case, and still do initial link training. Signed-off-by: Eric Yang <Eric.Yang2@amd.com> Reviewed-by: Tony Cheng <Tony.Cheng@amd.com> Acked-by: Leo Li <sunpeng.li@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/amd/display/dc/core/dc_link.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index 564f140d4e60..9f551fc68622 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -706,12 +706,26 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
if (memcmp(&link->dpcd_caps, &prev_dpcd_caps, sizeof(struct dpcd_caps)))
same_dpcd = false;
}
- /* Active dongle downstream unplug */
+ /* 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 (prev_sink != NULL)
+ if (prev_sink != NULL) {
+ /* Downstream unplug */
dc_sink_release(prev_sink);
+ } else {
+ /* Empty dongle plug in */
+ for (i = 0; i < LINK_TRAINING_MAX_VERIFY_RETRY; i++) {
+ int fail_count = 0;
+
+ dp_verify_link_cap(link,
+ &link->reported_link_cap,
+ &fail_count);
+
+ if (fail_count == 0)
+ break;
+ }
+ }
return true;
}