Hi, Emil On 08/31/2018 02:30 PM, Emil Velikov wrote:
Hi Thomas,
On 31 August 2018 at 12:54, Thomas Hellstrom thellstrom@vmware.com wrote:
To determine whether a device node is a drm device node or not, the code currently compares the node's major number to the static drm major device number.
This breaks the standalone vmwgfx driver on XWayland dri clients,
Any particular reason why the code doesn't use a fixed node there? It will make the diff vs the in-kernel driver a bit smaller.
Because then it won't be able to interoperate with other in-tree drivers, like virtual drm drivers or passthrough usb drm drivers. There is no clean way to share the minor number allocation with in-tree drm, so standalone vmwgfx is using dynamic major allocation.
and any future attempt to introduce dynamic device numbers for drm.
I'm not sure how well any such attempt will pan out, regardless of the libdrm checks.
Namely: the static 226 has been used by a number of tools that interpose the libc' ioctl function. There could be others that also depend on it.
True, in any case for existing drivers changing static 226 to something else is at least 10+ years away according to Linus' policy, so the main issue here is really to get rid of a big annoyance in the standalone vmwgfx case.
/Thomas
Personally, I'd go with the kernel developers decision.
Dave, Daniel, others Should we keep or drop the major == 226 checks.
Thanks Emil