[PATCH] drm: virtio: reinstate drm_virtio_set_busid()

[Dave Airlie]

On 4 October 2016 at 03:43, Laszlo Ersek <lersek at redhat.com> wrote:
> Before commit a325725633c2 ("drm: Lobotomize set_busid nonsense for !pci
> drivers"), several DRM drivers for platform devices used to expose an
> explicit "drm_driver.set_busid" callback, invariably backed by
> drm_platform_set_busid().
>
> Commit a325725633c2 removed drm_platform_set_busid(), along with the
> referring .set_busid field initializations. This was justified because
> interchangeable functionality had been implemented in drm_dev_alloc() /
> drm_dev_init(), which DRM_IOCTL_SET_VERSION would rely on going forward.
>
> However, commit a325725633c2 also removed drm_virtio_set_busid(), for
> which the same consolidation was not appropriate: this .set_busid callback
> had been implemented with drm_pci_set_busid(), and not
> drm_platform_set_busid(). The error regressed Xorg/xserver on QEMU's
> "virtio-vga" card; the drmGetBusid() function from libdrm would no longer
> return stable PCI identifiers like "pci:0000:00:02.0", but rather unstable
> platform ones like "virtio0".
>
> Reinstate drm_virtio_set_busid() with judicious use of
>
>   git checkout -p a325725633c2^ -- drivers/gpu/drm/virtio

Thanks guys, I've pushed this into drm-next.

Dave.