I recently tried updating my MacBook to 22.04 and after the install when I booted back into Ubuntu I saw that I had a problem with the graphics driver. I can log in but about 3/4 of the screen's background is solid white. Also some images on web pages, the background of Chrome when I open a new tab, etc. is sometimes Magenta.
Playing around this this I've found that:
- If I boot from a USB stick with 22.04 on it the screen comes up almost entirely white. The graphics driver is not working correctly.
- If I instead boot using Safe Graphics the screen comes up with the background wallpaper as I expect.
- If I interrupt the boot sequence and boot from the previous kernel then the graphics work fine.
When the graphics are not working I see the error "No ums support in radeon module". I've read about this error and various places say to remove "nomodeset" from Grub. I tried that and it didn't fix the problem.
I've read others complaining about such problems with older versions of Ubuntu (like 16.04, etc.) but my Macbook has been able to use the graphics driver all the way up until this recent attempt to update from 21.10 -> 22.04.
I have a Venus XT [Radeon HD 8870M / R9 M270X/M370X] [1002:6821] (rev 83) graphics card. My fear is that with Ubuntu 22.04, support for this card has not only been unsupported but dropped. My hope is that perhaps unblacklisting the driver (not sure about this) and perhaps downloading and building an old driver might cause it to work. I thought of biting the bullet and re-installing Ubuntu 22.04 from the USB stick but when the Try Ubuntu wouldn't even show me that the graphics driver was not without it's issues I assume a full re-install will leave me in the same boat.
Anybody else know how I can fix this?
Some subsequent kernel update has resolved my issue. Apparently somebody eventually fixed the driver.