diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.19.8/0964-drm-amd-display-Don-t-skip-link-training-for-empty-d.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.19.8/0964-drm-amd-display-Don-t-skip-link-training-for-empty-d.patch | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.19.8/0964-drm-amd-display-Don-t-skip-link-training-for-empty-d.patch b/common/recipes-kernel/linux/linux-yocto-4.19.8/0964-drm-amd-display-Don-t-skip-link-training-for-empty-d.patch new file mode 100644 index 00000000..0c34cda3 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.19.8/0964-drm-amd-display-Don-t-skip-link-training-for-empty-d.patch @@ -0,0 +1,60 @@ +From 6c4a258ac11941ee18354cb8b2b8b923803f061e Mon Sep 17 00:00:00 2001 +From: Eric Yang <Eric.Yang2@amd.com> +Date: Fri, 23 Nov 2018 05:55:20 -0500 +Subject: [PATCH 0964/2940] 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> +--- + drivers/gpu/drm/amd/display/dc/core/dc_link.c | 18 ++++++++++++++++-- + 1 file 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 1bebb60ac629..30ab9b7a161c 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; + } + +-- +2.17.1 + |