diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2018-10-05 11:47:32 +0200 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2018-10-05 18:06:49 +0200 |
| commit | 6b6fce62f65c19590bee8102f7946a26eaf0b054 (patch) | |
| tree | 1e2f7100acc6915317429c940294252021817a74 /drivers/gpu/drm/drm_modeset_helper.c | |
| parent | e6a3e405b54804efbf50e97c8c4460099be03e1f (diff) | |
drm: Unexport primary plane helpers
Well except the destroy helper, which isn't really a primary helper
but generally useful, if mislabelled.
v2: Keep some of the nice comments about the limitations of the
primarmy plane helpers, and put them into the kerneldoc for
drm_crtc_init() (Sam).
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181005094732.31353-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu/drm/drm_modeset_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_modeset_helper.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c index f1c24ab0ef09..9150fa385bba 100644 --- a/drivers/gpu/drm/drm_modeset_helper.c +++ b/drivers/gpu/drm/drm_modeset_helper.c @@ -146,6 +146,21 @@ static struct drm_plane *create_primary_plane(struct drm_device *dev) * Initialize a CRTC object with a default helper-provided primary plane and no * cursor plane. * + * Note that we make some assumptions about hardware limitations that may not be + * true for all hardware: + * + * 1. Primary plane cannot be repositioned. + * 2. Primary plane cannot be scaled. + * 3. Primary plane must cover the entire CRTC. + * 4. Subpixel positioning is not supported. + * 5. The primary plane must always be on if the CRTC is enabled. + * + * This is purely a backwards compatibility helper for old drivers. Drivers + * should instead implement their own primary plane. Atomic drivers must do so. + * Drivers with the above hardware restriction can look into using &struct + * drm_simple_display_pipe, which encapsulates the above limitations into a nice + * interface. + * * Returns: * Zero on success, error code on failure. */ |