Non-deterministically boot into dark screen with Raven Ridge
Brief summary of the problem:
My laptop (Ryzen 7 Pro CPU with integrated Raven Ridge GPU) boots into dark screen more often than
not. Screen blackness correlates with a line in the systemd journal
that says RAM width Nbits DDR4, where N is either 128 (resulting in
dark screen) or 64 (resulting in a healthy boot). The number seems to
be chosen at random with bias towards 128. This has been going on for
a while so here is some statistics:
- 356 boots proceed far enough to attempt mode setting.
- 82 boots set RAM width to 64 bits and presumably succeed.
- 274 boots set RAM width to 128 bits and presumably fail.
The issue is prevented with the nomodeset kernel option.
See also:
Hardware description:
- CPU:
AMD Ryzen 7 PRO 2700U w/ Radeon Vega Mobile Gfx - GPU:
VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] (rev d0) - System Memory: 1 unit of
8ATF1G64HZ-2G6E1(8GiB DDR4). - Display(s): A laptop screen, 1920 x 1080.
- Type of Diplay Connection: I have no idea.
System infomration:
- Distro name and Version: Arch Linux
- Kernel version: 5.8.0
- Custom kernel: linux-next
- AMD package version: I have no idea.
How to reproduce the issue:
Boot the specified kernel on the specified hardware. Repeat as needed until dark screen is observed.