Bug 110506

Summary: i915 not handling the fake monitor well
Product: DRI Reporter: Wiktor <wiktor+freedesktop>
Component: DRM/IntelAssignee: Intel GFX Bugs mailing list <intel-gfx-bugs>
Status: RESOLVED WORKSFORME QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: normal    
Priority: medium CC: intel-gfx-bugs
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard: Triaged
i915 platform: i915 features:
Attachments:
Description Flags
dmesg output with drm.debug=0x1e log_buf_len=4M none

Description Wiktor 2019-04-24 09:45:25 UTC 
Hello,

I'm using Dell TB dock to connect external monitor. fwupd service, that checks for hardware components creates an extra fake monitor to probe information when MST controller is powered up without a monitor plugged in. That causes a series of flickers caused by the kernel graphics driver.

I've been asked to create this bug by fwupd maintainers as they believe it's "i915 not handling the fake monitor well".

See: https://github.com/hughsie/fwupd/issues/1105#issuecomment-476206640 for details.

Technical details (from https://01.org/linuxgraphics/documentation/how-report-bugs):

uname -m: x86_64
uname -r: 5.0.9-arch1-1-ARCH
Linux distribution: Arch
Machine or mother board model: Dell XPS 13 9350
Display connector: DP through Thunderbolt dock.

If there is more info needed please do tell me. Sorry in advance if I did miss something!
Comment 1 Lakshmi 2019-04-24 19:38:12 UTC 
Can you please attach the dmesg from boot with kernel parameters drm.debug=0x1e log_buf_len=4M?
Have you verified the issue with latest drmtip(https://cgit.freedesktop.org/drm-tip)?
Comment 2 Wiktor 2019-04-24 19:51:17 UTC 
Created attachment 144088 [details]
dmesg output with drm.debug=0x1e log_buf_len=4M
Comment 3 Wiktor 2019-04-24 19:54:44 UTC 
> Have you verified the issue with latest drmtip(https://cgit.freedesktop.org/drm-tip)?

Nope, I didn't. I actually never did that. Is there a guide how to do that? In the mean time I'll try to look for it in documentation (https://cgit.freedesktop.org/drm-tip/tree/Documentation).
Comment 4 Lakshmi 2019-04-29 06:12:21 UTC 
(In reply to Wiktor from comment #3)
> > Have you verified the issue with latest drmtip(https://cgit.freedesktop.org/drm-tip)?
> 
> Nope, I didn't. I actually never did that. Is there a guide how to do that?
> In the mean time I'll try to look for it in documentation
> (https://cgit.freedesktop.org/drm-tip/tree/Documentation).

Wiktor, this should help you https://01.org/linuxgraphics/documentation/build-guide-0 to build drmtip.
Comment 5 Lakshmi 2019-05-29 12:48:22 UTC 
@Wiktor, Any results from drmtip?
Comment 6 Wiktor 2019-05-29 13:45:47 UTC 
@Lakshmi, terribly sorry for the delay. Apparently I have grossly underestimated the amount of work I'd have in May. I'll get back to this ticket as soon as possible, as I don't like half-open tickets.
Comment 7 Lakshmi 2019-07-02 06:31:22 UTC 
No test results from drmtip for more than a month. Closing this issue as resolved works for me.

Please re-open if issue persists with latest drm-tip https://cgit.freedesktop.org/drm-tip and send dmesg from boot with kernel parameters drm.debug=0x1e log_buf_len=4M?

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.