Comment 7 for bug 1838176

Using Thinkpad T495s with Ryzen 3500U, on Ubuntu Budgie 18.04.

After upgrading to Kernel 5.3, I ran into black screen at login and general system instability, and lots of "failed to write reg ... wait reg ..." in dmesg. No issues when booting to Kernel 5.0.

Seems like there are several amdgpu firmeware upgrades in the past few week (https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/log/). Followed these instructions (source: https://www.phoronix.com/scan.php?page=news_item&px=Ubuntu-19.10-Radeon-RX-5700):

git clone git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
cd linux-firmware/
sudo cp -va amdgpu/ /lib/firmware/
sudo update-initramfs -u
reboot

After that, and I'm no longer seeing "failed to write reg ... wait reg ..." in dmesg, and system is generally more stable.