Hello Ilya,

On 11/11/21 01:45, Ilya Trukhanov wrote:

[snip]

quoted

Can you please share the kernel boot log for any of these cases too ?

Thanks a lot for the testing and providing the info!
 

quoted

This is just a guess though. Would be good if you could test following cases:

1) CONFIG_FB_EFI not set

/proc/fb:
0 amdgpu

dmesg: https://pastebin.com/c1BcWLEh

Suspend-to-RAM works.

quoted

2) CONFIG_FB_EFI=y and CONFIG_DRM_AMDGPU=m

/proc/fb before `modprobe amdgpu`:
0 EFI VGA

after:
0 amdgpu

dmesg: https://pastebin.com/vSsTw2Km

Suspend-to-RAM works.

quoted

3) CONFIG_SYSFB_SIMPLEFB=y and CONFIG_FB_SIMPLE=y

/proc/fb:
0 amdgpu
1 simple

dmesg: https://pastebin.com/ZSXnpLqQ

Suspend-to-RAM fails.

quoted

And for each check /proc/fb, the kernel boot log, and if Suspend-to-RAM works.

If the explanation above is correct, then I would expect (1) and (2) to work and
(3) to also fail.

Your testing confirms my assumptions. I'll check how this could be solved to
prevent the efifb driver to be probed if there's already a framebuffer device.

Best regards,
-- 
Javier Martinez Canillas
Linux Engineering
Red Hat