Created attachment 134797 [details]
journalctl of affected kernel
Machine: Acer Aspire One ZG5
Video outputs: one LCD display 1024x600, one VGA port with no monitor attached.
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GSE Express Integrated Graphics Controller (rev 03) (prog-if 00 [VGA controller])
Subsystem: Acer Incorporated [ALI] Device 015b
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at 58480000 (32-bit, non-prefetchable) [size=512K]
I/O ports at 60c0 [size=8]
Memory at 40000000 (32-bit, prefetchable) [size=256M]
Memory at 58500000 (32-bit, non-prefetchable) [size=256K]
[virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
Capabilities: <access denied>
Kernel driver in use: i915
Kernel modules: i915
This is the same machine affected in bug https://bugs.freedesktop.org/show_bug.cgi?id=98930 .
After updating to distro kernel 4.13.4 or 4.13.5, and rebooting, boot is normal until KMS takes over, then the display on the LCD gets garbled in a square area (800x800) at the left of the screen. The garbled area persists during the rest of the startup and into the login screen and makes the display unusable.
Previous kernel kernel-PAE-4.12.14-300.fc26.i686 does not garble the display, although it still shows a backtrace as described in #98930, as this is the exact same machine.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Acer Aspire One ZG5 32-bit with Fedora 26 and kernel-PAE-4.13.4-200.fc26.i686
2. Boot with updated kernel
Garbled screen in a square section when KMS takes over.
No screen corruption.
Using journalctl I have captured a dmesg output of the affected kernel. Look for the string "plane B assertion failure, should be off on pipe B but is still active".
*** This bug has been marked as a duplicate of bug 102931 ***