Regression on the sun4i-drm driver by cma helper change

[Icenowy Zheng]

Hi,

Today, during testing the Banana Pi M2 Zero HDMI patch, I found a
regression on the sun4i-drm driver, which happenes because of the cma
helper change.

The bad commit is 894a677f4b3e6d2ab8d01bb46c1fbd5f92e4591b ("drm/cma-
helper: Use the generic fbdev emulation").

If this commit is present, sun4i_framebuffer_init() will return
-ENODEV, because of the call of drm_client_new(). In this case sun4i-
drv will fail to probe, and all components will be unbound.

By reverting the commit, sun4i-drv loads and HDMI output is correct.

Could anyone investigate into this, please?

Thanks,
Icenowy