drm: virtio: reinstate drm_virtio_set_busid()

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

Cc: Daniel Vetter <[email protected]>
Cc: Emil Velikov <[email protected]>
Cc: Gerd Hoffmann <[email protected]>
Cc: Gustavo Padovan <[email protected]>
Cc: Hans de Goede <[email protected]>
Cc: Joachim Frieben <[email protected]>
Cc: [email protected] # v4.8
Reported-by: Joachim Frieben <[email protected]>
Fixes: a325725633c26aa66ab940f762a6b0778edf76c0
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1366842
Signed-off-by: Laszlo Ersek <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>

0 files changed, 0 insertions, 0 deletions