When a property has the type DRM_MODE_PROP_BITMASK, the value field stores a bitshift, not a bitmask, which can be surprising.
Signed-off-by: Simon Ser contact@emersion.fr Cc: Pekka Paalanen pekka.paalanen@collabora.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Leandro Ribeiro leandro.ribeiro@collabora.com --- include/drm/drm_property.h | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/include/drm/drm_property.h b/include/drm/drm_property.h index bbf5c1fdd7b0..f3ea7f97f372 100644 --- a/include/drm/drm_property.h +++ b/include/drm/drm_property.h @@ -37,6 +37,11 @@ * * For enumeration and bitmask properties this structure stores the symbolic * decoding for each value. This is used for example for the rotation property. + * + * If the property has the type &DRM_MODE_PROP_BITMASK, @value stores a + * bitshift, not a bitmask. In other words, the enum entry is enabled if the + * bit number @value is set in the property's value. This enum entry has the + * bitmask ``1 << value``. */ struct drm_property_enum { uint64_t value;