Bug 6485

Summary: Potential issue parsing EDID in firmware
Product: [Hardware Platforms] MinnowBoard MAX Reporter: John 'Warthog9' Hawley <warthog9>
Component: hw-minnowmaxAssignee: He, Tim <tim.he>
Status: RESOLVED FIXED QA Contact:
Severity: major    
Priority: Medium CC: sjolley.yp.pm
Version: unspecified   
Target Milestone: Production Release   
Hardware: MinnowBoard Max   
OS: Multiple   
Whiteboard:
OS type for building Yocto: --- Type of Regression: ---
Verified: Documentation change: No (bug/feature does not impact docs)
Attachments:
Description Flags
Lilliput xrandr output
none
BenQ none

Description John 'Warthog9' Hawley 2014-06-26 21:10:35 UTC 
EFI Shell version 2.40 [1.0]
Current running mode 1.1.2

Minnowboard Max board version: A1

Certain monitors EDID seem to have issues with the MinnowBoard MAX, in particular with the Lilliput screens.  Larger, more normal, monitors (eg: Dell), seem to be fine, but the Lilliputs very often won't give a display at all, sometimes requiring odd re-plugging in, or VT switching to resolve.

It was thought this might get fixed with the A1 from the A0 (also seen there), but this has come up on the A1 now as well.

This bug is meant as a tracking bug with respect to that.
Comment 1 John 'Warthog9' Hawley 2014-06-27 01:28:13 UTC 
Additional information:

Darren and I both have a Lilliput 7in screen, looks to be 619A

http://lilliputweb.net/resistive-touch-screen-lcd-monitors/7-inch-monitors/619a.html

Darren noted that with his A0 board it worked fine, with his A1 board it did not.

I just tested mine (with a cable borrowed from Pidge), and it works more or less fine.

I took my board, and tested it with Darren's monitor, and was able to replicate what he's seeing.

If I use my board, Darren's screen and the cable I borrowed - I get display on Darren's screen from my board.

If I use my A0 board, my screen and Pidge's cable: I get no display

If I use my A0 board, my Dell screen, and a different cable (hdmi <-> dvi w/ adapter), it does work
Comment 2 John 'Warthog9' Hawley 2014-07-09 21:47:24 UTC 
Created attachment 2034 [details]
Lilliput xrandr output
Comment 3 John 'Warthog9' Hawley 2014-07-09 21:58:16 UTC 
Created attachment 2035 [details]
BenQ
Comment 4 John 'Warthog9' Hawley 2014-07-09 21:59:44 UTC 
(In reply to comment #3)
> Created attachment 2035 [details]
> BenQ

Model: Q24WS manufactured circa 2007
Comment 5 John 'Warthog9' Hawley 2014-07-09 22:28:13 UTC 
Ok a More detailed problem description:

With some monitors the minnow just won't display anything, even at firmware boot time.  It's not clear what the exact problem is.  We have noticed an oddity with even specific cables which I'll detail:

Monitors Known to work regardless of cable used seemingly:

- Dell U2312HM

Monitors Known to have issues:

- Lilliput 7in screen, looks to be 619A
  http://lilliputweb.net/resistive-touch-screen-lcd-monitors/7-inch-monitors/619a.html
  EDID information from xrandr attached

- BENQ Q24WS
  EDID information from xrandr attached

Cables used:
- micro-hdmi to full hdmi cable pulled from FRI2 box: works (marked A, in John's posession)
- micro-hdmi to full hdmi cable pulled from FRI2 box: doesn't work (marked B, on Darren's desk)
- full hdmi to dvi cable w/ micro-hdmi to hdmi adapter: works
- micro-hdmi to full hdmi adapter attached to hdmi cable: doesn't work

Most testing was done with the Lilliput screens, which we have two of and act consistently between the two.  Using cable marked B, no MinnowBoard MAX A1 to Lilliput ever works.  Only changing the cable from the B to the A cable, all tests worked.
Comment 6 John 'Warthog9' Hawley 2014-08-14 23:17:22 UTC 
The work-around seems to work, so I'm going to close this.  We can track the issue not being "fixed" in the GOP driver in 6599