diff options
| author | Maxime Ripard <maxime@cerno.tech> | 2021-06-16 16:15:29 +0200 |
|---|---|---|
| committer | Maxime Ripard <maxime@cerno.tech> | 2021-06-23 14:32:27 +0200 |
| commit | bacbab58f09dcf7c9a52b9f11388b3e25b9daa5f (patch) | |
| tree | 6358fbcfee0ccb6f03f078ec984967025f3cf0e8 /include/drm/drm_connector.h | |
| parent | c48935ab6b1280a80b38405369e88470f49809f4 (diff) | |
drm: Mention the power state requirement on side-channel operations
The drm_connector detect, drm_dp_aux transfer and mipi_dsi_host
operations typically require to access their underlying device to
perform what is expected of them.
However, there's no guarantee on the fact that the device has been
enabled through atomic_enable or similar that will usually power the
device. The access to an unpowered device is then an undefined behaviour
ranging from the access being ignored to a hard CPU hang.
Let's document that expectation to avoid as much as possible those
consequences.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210616141529.630719-3-maxime@cerno.tech
Diffstat (limited to 'include/drm/drm_connector.h')
| -rw-r--r-- | include/drm/drm_connector.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index 714d1a01c065..0a1d9a0fcbb2 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -848,6 +848,11 @@ struct drm_connector_funcs { * locks to avoid races with concurrent modeset changes need to use * &drm_connector_helper_funcs.detect_ctx instead. * + * Also note that this callback can be called no matter the + * state the connector is in. Drivers that need the underlying + * device to be powered to perform the detection will first need + * to make sure it's been properly enabled. + * * RETURNS: * * drm_connector_status indicating the connector's status. |