drm/fbdev-client: Skip DRM clients if modesetting is absent

Recent generations of Tegra have moved the display components outside of
host1x, leading to a device that has no CRTCs attached and hence doesn't
support any of the modesetting functionality. When this is detected, the
driver clears the DRIVER_MODESET and DRIVER_ATOMIC flags for the device.

Unfortunately, this causes the following errors during boot:

    [      15.418958] ERR KERN drm drm: [drm] *ERROR* Failed to register client: -95
    [      15.425311] WARNING KERN drm drm: [drm] Failed to set up DRM client; error -95

These originate from the fbdev client checking for the presence of the
DRIVER_MODESET flag and returning -EOPNOTSUPP. However, if a driver does
not support DRIVER_MODESET this is entirely expected and the error isn't
helpful.

Prevent this misleading error message by setting up the DRM clients only
if modesetting is enabled.

Changes in v2:
- use DRIVER_MODESET check to avoid registering any clients

Reported-by: Jonathan Hunter <[email protected]>
Signed-off-by: Thierry Reding <[email protected]>
Acked-by: Jon Hunter <[email protected]>
Tested-by: Jon Hunter <[email protected]>
Reviewed-by: Thomas Zimmermann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Baryshkov <[email protected]>

0 files changed, 0 insertions, 0 deletions