| Message ID | kW7vylF0J6Nbh0g1bvYEuG1DgaYRFH0ovsnD0c0SeU@cp3-web-024.plabs.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] drm: rework description of primary and cursor planes | expand |
On Thu, Dec 10, 2020 at 03:50:35PM +0000, Simon Ser wrote: > If a CRTC is missing a legacy primary plane pointer, a lot of things > will be broken for user-space: fbdev stops working and the entire legacy > uAPI stops working. > > Require all drivers to populate drm_crtc.primary to prevent these > issues. Warn if it's NULL. > > Signed-off-by: Simon Ser <contact@emersion.fr> > Cc: Daniel Vetter <daniel@ffwll.ch> > Cc: Pekka Paalanen <ppaalanen@gmail.com> For context we even kinda guarantee that xrgb8888 is available, with in-kernel conversion, because just too much of the simplistic userspace falls over otherwise. If we don't have a primary plane then kms is practically useless I think :-) Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > drivers/gpu/drm/drm_mode_config.c | 3 +++ > drivers/gpu/drm/drm_plane.c | 2 +- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c > index 2c73a60e8765..fbe680035129 100644 > --- a/drivers/gpu/drm/drm_mode_config.c > +++ b/drivers/gpu/drm/drm_mode_config.c > @@ -639,6 +639,9 @@ void drm_mode_config_validate(struct drm_device *dev) > } > > drm_for_each_crtc(crtc, dev) { > + WARN(!crtc->primary, "Missing primary plane on [CRTC:%d:%s]\n", > + crtc->base.id, crtc->name); > + > if (crtc->primary) { > WARN(!(crtc->primary->possible_crtcs & BIT(crtc->index)), > "Bogus primary plane possible_crtcs: [PLANE:%d:%s] must be compatible with [CRTC:%d:%s]\n", > diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c > index 5d33ca9f0032..49b0a8b9ac02 100644 > --- a/drivers/gpu/drm/drm_plane.c > +++ b/drivers/gpu/drm/drm_plane.c > @@ -57,7 +57,7 @@ > * Legacy uAPI doesn't expose the primary and cursor planes directly. DRM core > * relies on the driver to set the primary and optionally the cursor plane used > * for legacy IOCTLs. This is done by calling drm_crtc_init_with_planes(). All > - * drivers should provide one primary plane per CRTC to avoid surprising legacy > + * drivers must provide one primary plane per CRTC to avoid surprising legacy > * userspace too much. > */ > > -- > 2.29.2 > >
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c index 2c73a60e8765..fbe680035129 100644 --- a/drivers/gpu/drm/drm_mode_config.c +++ b/drivers/gpu/drm/drm_mode_config.c @@ -639,6 +639,9 @@ void drm_mode_config_validate(struct drm_device *dev) } drm_for_each_crtc(crtc, dev) { + WARN(!crtc->primary, "Missing primary plane on [CRTC:%d:%s]\n", + crtc->base.id, crtc->name); + if (crtc->primary) { WARN(!(crtc->primary->possible_crtcs & BIT(crtc->index)), "Bogus primary plane possible_crtcs: [PLANE:%d:%s] must be compatible with [CRTC:%d:%s]\n", diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c index 5d33ca9f0032..49b0a8b9ac02 100644 --- a/drivers/gpu/drm/drm_plane.c +++ b/drivers/gpu/drm/drm_plane.c @@ -57,7 +57,7 @@ * Legacy uAPI doesn't expose the primary and cursor planes directly. DRM core * relies on the driver to set the primary and optionally the cursor plane used * for legacy IOCTLs. This is done by calling drm_crtc_init_with_planes(). All - * drivers should provide one primary plane per CRTC to avoid surprising legacy + * drivers must provide one primary plane per CRTC to avoid surprising legacy * userspace too much. */
If a CRTC is missing a legacy primary plane pointer, a lot of things will be broken for user-space: fbdev stops working and the entire legacy uAPI stops working. Require all drivers to populate drm_crtc.primary to prevent these issues. Warn if it's NULL. Signed-off-by: Simon Ser <contact@emersion.fr> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Pekka Paalanen <ppaalanen@gmail.com> --- drivers/gpu/drm/drm_mode_config.c | 3 +++ drivers/gpu/drm/drm_plane.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-)