diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.14.71/4929-drm-amd-display-Read-AUX-channel-even-if-only-status.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.14.71/4929-drm-amd-display-Read-AUX-channel-even-if-only-status.patch | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.14.71/4929-drm-amd-display-Read-AUX-channel-even-if-only-status.patch b/common/recipes-kernel/linux/linux-yocto-4.14.71/4929-drm-amd-display-Read-AUX-channel-even-if-only-status.patch new file mode 100644 index 00000000..290ce36f --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.14.71/4929-drm-amd-display-Read-AUX-channel-even-if-only-status.patch @@ -0,0 +1,47 @@ +From aa030c7b66c1ea84ed86779ca7891b86b1616eb8 Mon Sep 17 00:00:00 2001 +From: "Leo (Sunpeng) Li" <sunpeng.li@amd.com> +Date: Tue, 26 Jun 2018 10:50:16 -0400 +Subject: [PATCH 4929/5725] drm/amd/display: Read AUX channel even if only + status byte is returned + +[Why] +get_channel_status() can return 0 in returned_bytes, and report a +successful operation result. This is because it prunes the first status +byte out. This was preventing read_channel_reply() from being called +(due to the faulty condition), and consequently preventing the AUX +reply status from being set. + +[How] +Fix the conditional so that it accounts for when get_channel_status() +returns 0 bytes read. + +[Fixes] +Fixes possible edid read failures during S3 resume, where we are now +relying on DRM's DP AUX handling. This was an regression introduced by: + + Author: Harry Wentland <harry.wentland@amd.com> + drm/amd/display: Return aux replies directly to DRM + +Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com> +Reviewed-by: Harry Wentland <Harry.Wentland@amd.com> +Signed-off-by: Alex Deucher <alexander.deucher@amd.com> +--- + drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c +index d108ccf..08c9d73 100644 +--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c ++++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c +@@ -671,7 +671,7 @@ int dc_link_aux_transfer(struct ddc_service *ddc, + case AUX_CHANNEL_OPERATION_SUCCEEDED: + res = returned_bytes; + +- if (res <= size && res > 0) ++ if (res <= size && res >= 0) + res = engine->funcs->read_channel_reply(engine, size, + buffer, reply, + &status); +-- +2.7.4 + |