diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-05-15 11:11:35 +0200 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-05-23 16:36:06 +0200 |
| commit | 9de5d4a61cc2a99634e3b51bda0f8e2fdd8f4287 (patch) | |
| tree | b7bf4043a742961f4e94438ee8a86a9d863f2ae9 /include/drm/drm_crtc.h | |
| parent | 3eb220a5319169fb44dcfe1944c731424c2bee5f (diff) | |
drm/doc: Document adjusted/request modes a bit better
Laurent started a massive discussion on IRC about this. Let's try to
document common usage a bit better.
v2: Cross-links+typos.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170515091136.26307-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'include/drm/drm_crtc.h')
| -rw-r--r-- | include/drm/drm_crtc.h | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index adf4e91a9399..b6e3713bd7a9 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -90,8 +90,6 @@ struct drm_plane_helper_funcs; * @plane_mask: bitmask of (1 << drm_plane_index(plane)) of attached planes * @connector_mask: bitmask of (1 << drm_connector_index(connector)) of attached connectors * @encoder_mask: bitmask of (1 << drm_encoder_index(encoder)) of attached encoders - * @adjusted_mode: for use by helpers and drivers to compute adjusted mode timings - * @mode: current mode timings * @mode_blob: &drm_property_blob for @mode * @state: backpointer to global drm_atomic_state * @@ -131,9 +129,33 @@ struct drm_crtc_state { u32 connector_mask; u32 encoder_mask; - /* adjusted_mode: for use by helpers and drivers */ + /** + * @adjusted_mode: + * + * Internal display timings which can be used by the driver to handle + * differences between the mode requested by userspace in @mode and what + * is actually programmed into the hardware. It is purely driver + * implementation defined what exactly this adjusted mode means. Usually + * it is used to store the hardware display timings used between the + * CRTC and encoder blocks. + */ struct drm_display_mode adjusted_mode; + /** + * @mode: + * + * Display timings requested by userspace. The driver should try to + * match the refresh rate as close as possible (but note that it's + * undefined what exactly is close enough, e.g. some of the HDMI modes + * only differ in less than 1% of the refresh rate). The active width + * and height as observed by userspace for positioning planes must match + * exactly. + * + * For external connectors where the sink isn't fixed (like with a + * built-in panel), this mode here should match the physical mode on the + * wire to the last details (i.e. including sync polarities and + * everything). + */ struct drm_display_mode mode; /* blob property to expose current mode to atomic userspace */ |