On Sat, 06 Mar 2021 10:56:49 +0000 Simon Ser contact@emersion.fr wrote:
On Friday, March 5th, 2021 at 9:28 AM, Pekka Paalanen ppaalanen@gmail.com wrote:
+/**
- DRM_CAP_DUMB_PREFERRED_DEPTH
- The preferred depth (in bits) for dumb buffers.
this is literally depth, not bits per pixel, right?
"Depth" is pretty ambiguous [1]. Maybe we should be more explicit here and say that it's the number of bits used to indicate the color of a single pixel? And maybe add a note that it's different from bits per pixel?
Yes, indeed. I was already assuming the meaning of "depth" in drmModeAddFB().
+/**
- DRM_CAP_PRIME
- Bitfield of supported PRIME sharing capabilities. See &DRM_PRIME_CAP_IMPORT
- and &DRM_PRIME_CAP_EXPORT.
- */
#define DRM_CAP_PRIME 0x5 +/**
- DRM_PRIME_CAP_IMPORT
- If this bit is set in &DRM_CAP_PRIME, the driver supports importing PRIME
- buffers.
What are PRIME buffers?
Will add something like:
PRIME buffers are exposed as dma-buf file descriptors. See Documentation/gpu/drm-mm.rst, section "PRIME Buffer Sharing".
Sounds good.
- */
#define DRM_PRIME_CAP_IMPORT 0x1 +/**
- DRM_PRIME_CAP_EXPORT
- If this bit is set in &DRM_CAP_PRIME, the driver supports exporting PRIME
- buffers.
What's the export API? HandleToFD()?
Yes. Will add a note about it. Same for import.
Cool.
+/**
- DRM_CAP_CRTC_IN_VBLANK_EVENT
- If set to 1, the kernel supports reporting the CRTC ID in
- &drm_event_vblank.crtc_id.
Does this not apply also to the pageflip / atomic completion event?
Both DRM_EVENT_VBLANK and DRM_EVENT_FLIP_COMPLETE use the struct drm_event_vblank, so yes. I'll mention these two events explicitly.
They do? Seems like I have been spoiled by the libdrm API that uses drmEventContext with different callbacks for these things.
Thanks, pq