Hi Sergey,

On Thu, 2020-02-20 at 11:21 +0300, Sergey Suloev wrote:

Hello, guys,

could anyone clarify the status of vc4 drm support on RPI 3A+ ?

I tried to build kernel 5.5 and 5.6-rc2 in 32bit and aarch64 
configurations with VC4 turned ON but both unsuccessful - vc4 drm driver 
is listed in memory but not working and not producing any typical DRM 
log output.

I managed to get my hands on a rpi3a+ and reproduce the issue. 'dmesg -lerr'
outputs this:

	bcm2835-power: Timeout waiting for grafx power OK

This is a known issue, see https://github.com/raspberrypi/linux/issues/3046.
I attached a device-tree patch in case you want to verify it fixes the issue on
your board.

@Stefan I guess I'm going to have to revert the pm patch, any comments before I
do?

Regards,
Nicolas