Created attachment 288907 [details]
Path for 5.4.27 to fix framebuffer
we have some ancient software which uses DirectFB to draw to the framebuffer during installation.
After upgrading from kernel 4.14.99 to 5.4.27 the framebuffer stall the GPU and only a black image was shown. This could be reprocuded on an Igel UD 7 (CARRIZO) and a Lenovo 14w (STONEY) lspci -vv is attached from both devices.
We did some more investigation to find the breaking change please see attached git bisect log:
6c8d74caa2fa33908ecd07fb1cf1b7bc629b367a is the first bad commit
After finding the bad commit we reverted the changes on the 5.4.27 and framebuffer started working again. Patch for reverting is also attached.
Created attachment 288909 [details]
lspci from lenovo 14w
Created attachment 288911 [details]
lspci from IGEL UD7
Created attachment 288913 [details]
git bisect log
Created attachment 288915 [details]
Reverting will break all systems with limited vram and large displays. Does this patch fix the issue?
Created attachment 288919 [details]
This might be a better option.
Thanks for the quick reply.
The first patch from comment 4 works
The second patch from comment 5 does not work