[Devel] [PATCH vz10] drm/virtio: decline the device with -ENODEV when modesetting is off

[Vasileios Almpanis]

> Our kernels disable modesetting by default, see 7932a11226c8 ("drm:
checkpatch.pl complains about description style here.
Please use git commit description style 'commit <12+ chars of sha1>
> Disable modeset by default"), so on a machine that was not booted with
> "modeset" every KMS driver declines the device it was offered. Of 23
> existing upstream drm drivers, 21 report -ENODEV in such case, which
> really_probe() reports as "rejects match" at debug level. virtio_gpu
> returns -EINVAL instead, which the same function reports as
> 
>   virtio_gpu virtio0: probe with driver virtio_gpu failed with error -22
> 
> at error level, for a device the driver was never going to drive. It is
> the only device error in the log of an otherwise healthy machine, and
> the devices/error_logs selftest reports it, correctly.
> 
> Return -ENODEV, as the other drivers do. Nothing else changes: the probe
> still does not happen and no drm device appears.
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-139680
> Feature: fix vz kernel
Please add Fixes tag.

-- 
Vasileios Almpanis <vasileios.almpanis at virtuozzo.com>