#10824 LOW Not Tri: OFW test /camera becomes flaky on XO-1.5 if loose serial cable plugged in; Linux OK(?)

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#10824: OFW test /camera becomes flaky on XO-1.5 if loose serial cable plugged in;
Linux OK(?)
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 Reporter:  greenfeld            |                 Owner:  wmb at firmworks.com                
     Type:  defect               |                Status:  new                              
 Priority:  low                  |             Milestone:  Not Triaged                      
Component:  ofw - open firmware  |               Version:  Development build as of this date
 Keywords:                       |           Next_action:  diagnose                         
 Verified:  0                    |   Deployment_affected:                                   
Blockedby:                       |              Blocking:                                   
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 The Open Firmware-based "test /camera" seems flaky on certain XO-1.5s,
 potentially much moreso in Q3A64 than Q3A62.  When it is flaky, still
 images and lots of line and dot-based corruption will appear in the on-
 screen video.

 It is unclear if Linux-based camera recording is affected, but there
 definitely is not any extreme noise or major corruption in Linux when used
 with Record or other Sugar activities.

 My best guess at this time is this is related to if a serial cable is
 plugged into the XO-1.5 or not.  Adding a serial cable can cause this
 corruption; removing it gets rid of it with the same laptop.  Both D4 & D6
 motherboards seem to be affected.

 This might be an OFW issue, or maybe a HW issue; or maybe just an errata.

 Reproduction:
  1. Plug in a serial cable to an XO-1.5, but do not attach it to a USB
 adapter, etc.
  2. With an insecure XO-1.5, run "test /camera" more than once after
 getting to the OFW prompt.
  3. Alternatively, run the full OFW test suite, although the first
 approach probably is easier.
  4. If the user's image basically becomes a still image (and the test has
 not stopped yet) and the image looks extremely corrupted, then you have
 hit this issue.  I don't know if any particular level of RFI in the area
 is necessary.
  5. Remove the serial cable from the XO-1.5 and repeat; the issue should
 go away.

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Ticket URL: <http://dev.laptop.org/ticket/10824>
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