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Code Issues Releases Wiki Activity

drm/amd/display: Add comments to hdcp property change code

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[Why]
These comments are helpful in understanding which case each if
statement handles.

[How]
Add comments for state transitions (9 possible cases)

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Zhan Liu <zhan.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Bhawanpreet Lakha 2019-09-26 17:44:50 -04:00 committed by Alex Deucher
parent 97f6c91787
commit 31c0ed90b9
1 changed files with 24 additions and 2 deletions
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26
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
View file

@ -7238,26 +7238,35 @@ static bool is_content_protection_different(struct drm_connector_state *state,
struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
struct dm_connector_state *dm_con_state = to_dm_connector_state(connector->state);
/* Handle: Type0/1 change */
if (old_state->hdcp_content_type != state->hdcp_content_type &&
state->content_protection != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
return true;
}
/* CP is being re enabled, ignore this */
/* CP is being re enabled, ignore this
*
* Handles: ENABLED -> DESIRED
*/
if (old_state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
state->content_protection = DRM_MODE_CONTENT_PROTECTION_ENABLED;
return false;
}
/* S3 resume case, since old state will always be 0 (UNDESIRED) and the restored state will be ENABLED */
/* S3 resume case, since old state will always be 0 (UNDESIRED) and the restored state will be ENABLED
*
* Handles: UNDESIRED -> ENABLED
*/
if (old_state->content_protection == DRM_MODE_CONTENT_PROTECTION_UNDESIRED &&
state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED)
state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
/* Check if something is connected/enabled, otherwise we start hdcp but nothing is connected/enabled
* hot-plug, headless s3, dpms
*
* Handles: DESIRED -> DESIRED (Special case)
*/
if (dm_con_state->update_hdcp && state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
connector->dpms == DRM_MODE_DPMS_ON && aconnector->dc_sink != NULL) {
@ -7265,12 +7274,25 @@ static bool is_content_protection_different(struct drm_connector_state *state,
return true;
}
/*
* Handles: UNDESIRED -> UNDESIRED
* DESIRED -> DESIRED
* ENABLED -> ENABLED
*/
if (old_state->content_protection == state->content_protection)
return false;
/*
* Handles: UNDESIRED -> DESIRED
* DESIRED -> UNDESIRED
* ENABLED -> UNDESIRED
*/
if (state->content_protection != DRM_MODE_CONTENT_PROTECTION_ENABLED)
return true;
/*
* Handles: DESIRED -> ENABLED
*/
return false;
}