[PATCH libdrm] libdrm: Allow dynamic drm majors on linux

[Michel Dänzer]

[ Adding the amd-gfx list ]

On 2018-08-31 3:05 p.m., Thomas Hellstrom wrote:
> On 08/31/2018 02:30 PM, Emil Velikov wrote:
>> On 31 August 2018 at 12:54, Thomas Hellstrom <thellstrom at 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.

I wonder why I haven't heard of any of these issues with the standalone
version of amdgpu shipped in packaged AMD releases. Does that also use a
different major number? If yes, maybe it's just that nobody has tried
Xwayland clients with that driver. If no, how does it avoid the other
issues described above?


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer