drm: add support for tiled/compressed/etc modifier in addfb2
In DRM/KMS we are lacking a good way to deal with tiled/compressed
formats. Especially in the case of dmabuf/prime buffer sharing, where
we cannot always rely on under-the-hood flags passed to driver specific
gem-create ioctl to pass around these extra flags.
The proposal is to add a per-plane format modifier. This allows to, if
necessary, use different tiling patters for sub-sampled planes, etc.
The format modifiers are added at the end of the ioctl struct, so for
legacy userspace it will be zero padded.
v1: original
v1.5: increase modifier to 64b
v2: Incorporate review comments from the big thread, plus a few more.
- Add a getcap so that userspace doesn't have to jump through hoops.
- Allow modifiers only when a flag is set. That way drivers know when
they're dealing with old userspace and need to fish out e.g. tiling
from other information.
- After rolling out checks for ->modifier to all drivers I've decided
that this is way too fragile and needs an explicit opt-in flag. So
do that instead.
- Add a define (just for documentation really) for the "NONE"
modifier. Imo we don't need to add mask #defines since drivers
really should only do exact matches against values defined with
fourcc_mod_code.
- Drop the Samsung tiling modifier on Rob's request since he's not yet
sure whether that one is accurate.
v3:
- Also add a new ->modifier[] array to struct drm_framebuffer and fill
it in drm_helper_mode_fill_fb_struct. Requested by Tvrkto Uruslin.
- Remove TODO in comment and add code comment that modifiers should be
properly documented, requested by Rob.
Cc: Rob Clark <robdclark@gmail.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Rob Clark <robdclark@gmail.com> (v1.5)
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index ad2934b..b15d720 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3314,6 +3314,12 @@
DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
return -EINVAL;
}
+
+ if (r->modifier[i] && !(r->flags & DRM_MODE_FB_MODIFIERS)) {
+ DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
+ r->modifier[i], i);
+ return -EINVAL;
+ }
}
return 0;
@@ -3327,7 +3333,7 @@
struct drm_framebuffer *fb;
int ret;
- if (r->flags & ~DRM_MODE_FB_INTERLACED) {
+ if (r->flags & ~(DRM_MODE_FB_INTERLACED | DRM_MODE_FB_MODIFIERS)) {
DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
return ERR_PTR(-EINVAL);
}
@@ -3343,6 +3349,12 @@
return ERR_PTR(-EINVAL);
}
+ if (r->flags & DRM_MODE_FB_MODIFIERS &&
+ !dev->mode_config.allow_fb_modifiers) {
+ DRM_DEBUG_KMS("driver does not support fb modifiers\n");
+ return ERR_PTR(-EINVAL);
+ }
+
ret = framebuffer_check(r);
if (ret)
return ERR_PTR(ret);