Bug 204701

Summary: Latitude 7400 2-in-1: intermittent screen freezes (i915)
Product: Drivers Reporter: Leho Kraav (leho)
Component: Video(AGP)Assignee: Dave Airlie (airlied)
Status: RESOLVED INVALID    
Severity: normal    
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: 5.3.0-rc6 Subsystem:
Regression: No Bisected commit-id:
Attachments: dmesg.txt

Description Leho Kraav 2019-08-26 14:01:10 UTC 
Hardware: Dell Latitude 7400 2-in-1 with Wacom 0x48C9 touchscreen

Seemingly at random, this Coffeelake gen9 chip graphics engine is intermittently freezing on me. Mouse cursor has been in a Firefox web browser window at least on a few occurrences.

External screen, connected via Type C, also froze.

Kernel stays alive, because I could still reboot via magic sysrq and REISUB.

After rebooting, checking `journalctl -b -1` reveals zero error messages from Xorg, or kernel.

It feels like i915 might be involved with maybe one of the performance parameters (dc, psr, fbc, rc6, etc) being incompatible with this relatively new hardware.

There's also another known bug with this (touch)screen at designware i2c level https://bugzilla.kernel.org/show_bug.cgi?id=204063

Of course, this might just be faulty hardware, but setting up testing a Win10 installation here is a large challenge. I'd like to exclude Linux software stack issues first.

Q: what kernel or i915 paramaters would you recommend I test first, to see if freezes can go away?
Comment 1 Leho Kraav 2019-08-26 14:04:13 UTC 
Created attachment 284609 [details]
dmesg.txt

PS I've run this same OS installation on DELL 7480 (KBL) for 2 years without any video issues, so it's either some new gen hardware incompatibility or broken hardware.
Comment 3 Leho Kraav 2019-09-10 14:29:56 UTC 
For anybody coming here from search, this is potentially a duplicate of https://bugzilla.kernel.org/show_bug.cgi?id=203317