From 6b6fce62f65c19590bee8102f7946a26eaf0b054 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 5 Oct 2018 11:47:32 +0200 Subject: drm: Unexport primary plane helpers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Sam Ravnborg Cc: Ville Syrjälä Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20181005094732.31353-1-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_modeset_helper.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/gpu/drm/drm_modeset_helper.c') 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. */ -- cgit v1.2.3