Bug 106467

Created attachment 139475 [details]
intel_reg dump

Hi! I have a Lenovo Yoga 910 which required option enable_rc6=0 in order to avoid screen corruption. With my distro's most recent update, we've picked up https://patchwork.kernel.org/patch/9644631/ and now I get screen corruption again. Here's a link to a 10-second video of what my laptop screen looks like: 
  https://drive.google.com/file/d/1Z7_Ce0NUKZhB9mIXpFFaeuMwXsmroV9m/view?usp=sharing

The screen corruption is intermittent. Having the screen updating, such as moving the mouse or playing a video on youtube, reduces the effect but it still flickers about once per second. I haven't seen any corruption when at a VT.

I've tried other settings that exist in the i915 driver but have been unable to find a workaround.

The link to intel_reg_dumper guide is 404 from https://01.org/linuxgraphics/documentation/how-report-bugs. I ran 'intel_reg dump' and attached that.

I was unable to get the video bios dump using the guide at https://01.org/linuxgraphics/documentation/development/how-dump-video-bios . The 'cat' step produces an 'input/output error' with a zero-byte file. (If I try cat after echo 0, I get an invalid argument error instead.) Let me know if you want an strace of the cat. This also produced errors in dmesg, the echo produced "Invalid PCI ROM header signature: expecting 0xaa55, got 0xffff" while the cat produced "Invalid mmio detected during user access".

Debian unstable/sid, xserver-xorg-video-intel package is version "2:2.99.917+git20171229-1", kernel is "4.16.5-1 (2018-04-29)".