#11871 NORM 12.1.0: XO-1.75 Open Firmware reports Data Abort during Linux kernel load if a PL2303 USB serial adapter is present

[Zarro Boogs per Child]

#11871: XO-1.75 Open Firmware reports Data Abort during Linux kernel load if a
PL2303 USB serial adapter is present
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           Reporter:  Quozl                |       Owner:  Quozl               
               Type:  defect               |      Status:  new                 
           Priority:  normal               |   Milestone:  12.1.0              
          Component:  ofw - open firmware  |     Version:  Development firmware
         Resolution:                       |    Keywords:                      
        Next_action:  package              |    Verified:  0                   
Deployment_affected:                       |   Blockedby:                      
           Blocking:                       |  
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Comment(by Quozl):

 Replying to [comment:7 pgf]:
 > i've reproduced, but it's not the bug i thought it was.
 >
 > while experiencing what was no doubt the Data Abort symptom over the
 weekend, i rebooted the machine with serial attached, and hit ESC for an
 ok prompt.  at that point i started getting the Keyboard Interrupt loop.
 since i had just been having trouble booting, and was now seeing a loop at
 the OFW commandline, i mistakenly thought i'd found the cause of the boot
 problem.
 > this seems like a regression.

 Agreed.  Raised #11887 to investigate, since it is a separate problem.

 > can you remind me of the use case for the new "USB serial access to OFW"
 feature?

 This is not a new feature, it has been there since the VIA demo board
 support in the biosload build (svn 1152), and XO-1.5 (svn 1154).  It was
 backported to XO-1 as part of the fixes for #10042 and #10043 in svn 1758.
 It was since broken on XO-1 and XO-1.5 by device naming changes, where USB
 is placed under PCI.  XO-1.75 exposed it because USB devices are now
 higher up the device hierarchy.

 I'm not aware of a use case, but I could speculate.  It allows access to
 Open Firmware on a unit where the keyboard has failed, and a USB keyboard
 is not available, but a USB serial device is available.  Perhaps it is no
 longer required, in which case #11887 can be closed by removing the code.

 If it is to remain, then either an alias or a fix to the device path is
 needed.

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Ticket URL: <http://dev.laptop.org/ticket/11871#comment:8>
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