| Summary: | Reproducible black screen glitches blackouts on Dell 2209WA DVI monitor with specific image using passive DP-DVI adaptor | ||||||||||||||
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| Product: | DRI | Reporter: | Chris Bainbridge <chris.bainbridge> | ||||||||||||
| Component: | DRM/Intel | Assignee: | Intel GFX Bugs mailing list <intel-gfx-bugs> | ||||||||||||
| Status: | CLOSED NOTOURBUG | QA Contact: | Intel GFX Bugs mailing list <intel-gfx-bugs> | ||||||||||||
| Severity: | normal | ||||||||||||||
| Priority: | medium | CC: | chris.bainbridge, intel-gfx-bugs | ||||||||||||
| Version: | unspecified | ||||||||||||||
| Hardware: | Other | ||||||||||||||
| OS: | All | ||||||||||||||
| Whiteboard: | |||||||||||||||
| i915 platform: | IVB | i915 features: | display/DP | ||||||||||||
| Attachments: |
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Description
Chris Bainbridge
2015-02-12 22:03:58 UTC
- The cables are Dell 50.7a2a0.041-r DVI-D so should be good - Surprisingly, I managed to reproduce the problem from a screenshot. Opening the screenshot in gimp and moving it to the monitor connected by passive miniDP>DVI adaptor is enough to cause the monitor to go black. - Manged to reproduce problem with only a fragment of the image. Opening this in gthumb and dragging it to the centre of the monitor immediately turns it off. Perhaps there is something specific about this pattern of data? Image attached (img_for_rot_left.png) - Reproduced with monitor in normal rotation (img_for_rot_normal.png) so this is not related to the image being rotated. - This can be reproduced with a single monitor, it is not something particular to a multi-monitor setup. - I tested this with 3 monitors and 4 DVI cables and 2 DP-DVI adaptors so it seems it is a design issue somewhere rather than a one off hardware fault. - Could this is caused by the passive miniDP>DVI adaptors? I was under the impression that this is unlikely since they are electrically very simple, just pass-through wires, and only about 15cm long. These are unbranded and came from a big Ebay seller so likely quite common. Created attachment 113428 [details]
img_for_rot_normal.png
Created attachment 113429 [details]
img_for_rot_left.png
Interesting. Please do a fresh boot with drm.debug=14 module parameter, reproduce the problem, then move the screenshot away to restore things to normal, and attach dmesg. Created attachment 113458 [details]
dmesg-drmdebug14
This is a log of 3.19.0 with drm.debug=14.
The screens are the internal eDP1 and an external DVI monitor on HDMI3 with passive mDP-DVI adaptor.
booted
logged in
used xrandr to set monitor to the right of laptop display
started eog with the test image
moved it to the external monitor at which point it started glitching
closed the eog window and the glitching stopped
I did the same test under OS X and there was no glitching. Everything worked fine. Created attachment 113459 [details]
fullsize_screenshot_for_normal_rotation.png
This is the full size 1680x1050 screenshot that I used for testing.
Note this the screenshot is of a normal rotation (landscape) monitor - the 90 degree rotation of the window is deliberate, it seems there is something specific about this pattern that triggers the bug.
I tested this same image under OS X on the same hardware and the bug did not occur.
This is the adaptor: http://www.ebay.co.uk/itm/Mini-Display-Port-to-DVI-I-Monitor-Adaptor-Converter-Cable-DisplayPort-24-5-/271098976593 The description says: Support Mini DisplayPort 1.1a compliant receiver offering 5.4Gbps bandwidth over 2 lanes. • Support video resolution 1080p, Supports 1920 x 1200 reduced blanking video resolution. • Powered from MiniDisplay source. • Compatibility: iMac, Mac Mini, Mac Pro, MacBook Air, MacBook Pro 13 inch, MacBook Pro 15 inch, MacBook Pro 17 inch. • Connectors: Mini Display Port Male to DVI-I Female 15cm. (Length includes connectors) Since it supports reduced blanking, I tried creating a reduced blanking mode: $ cvt -r 1680 1050 # 1680x1050 59.88 Hz (CVT 1.76MA-R) hsync: 64.67 kHz; pclk: 119.00 MHz Modeline "1680x1050R" 119.00 1680 1728 1760 1840 1050 1053 1059 1080 +hsync -vsync $ xrandr --newmode 1680x1050R 119.00 1680 1728 1760 1840 1050 1053 1059 1080 +hsync -vsync $ xrandr --addmode HDMI3 1680x1050R $ xrandr --output HDMI3 --mode 1680x1050R The new mode works without any glitching. If I do the previous test, and while the screen is glitching do "xrandr --output HDMI3 --mode 1680x1050R", the screen will immediately stop glitching. So perhaps OS X is using a reduced blanking mode, or some other altered timings, and that is why the glitching does not appear there. > The new mode works without any glitching.
Sorry that was incorrect! The new mode glitches. Maybe it is different somehow though.
In the regular mode, if I fullscreen the test image, and do "xrandr --output HDMI3 --mode 1680x1050", the screen starts immediately glitching.
If I then do "xrandr --output HDMI3 --mode 1680x1050R" it stops glitching.
But coming out of full screen it starts glitching again.
So perhaps the new mode alters the timings slightly or something, but the underlying glitch problem is still there.
At a quick glance it looks like the non-reduced mode is just barely within limits of the link. I think I've seen or heard of something similar, but can't find it now. I found some relevant thread on the Dell site, it seems this was an issue that affected several Dell models made around 2009. Final comment from Dell: "Posted by DELL-Chris I never could find a solid fix, several workarounds for PC, none for Macs. The issue does not occur for everyone and we could never replicate it in our lab." One user posted some images that reproduced the issue on a 2709W http://en.community.dell.com/support-forums/peripherals/f/3529/t/19257125 "I have the same issue with my 2709W (rev A01). I have made some experiments to find a way to reproduce the problem.... To reproduce the issue, just display the first image on your screen with a 1:1 pixel ratio (ex in your browser) and move the window, the screen should flicker while you move the window." That is basically what I see and the liney pattern of the posted images is similar to the basic pattern in mine (except my lines were text rather than solid lines). Some users reported that Sapphire fixed the problem with a BIOS update but for other manufacturers it was still an issue. Using active DisplayPort was the recommended workaround in the end. I did notice that the issue occurs from 55Hz up to 64Hz but 65Hz seems ok. Perhaps some power issue or signal integrity or minimum sync frequency is required... something odd anyway, nobody knows. So to conclude, it seems like the problem is probably not the passive DVI adaptors, but some unusual incompatibility between these particular monitors and particular graphics cards. (In reply to Chris Bainbridge from comment #11) > So to conclude, it seems like the problem is probably not the passive DVI > adaptors, but some unusual incompatibility between these particular monitors > and particular graphics cards. Thanks for the follow-up, and sorry for the delay. I suppose that leaves us with "not our bug". Thanks for the report. |
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