#4501 NORM Never A: OFW USB enumeration of slow disks

[Zarro Boogs per Child]

#4501: OFW USB enumeration of slow disks
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 Reporter:  wmb at firmworks.com    |       Owner:  wmb at firmworks.com
     Type:  defect               |      Status:  new              
 Priority:  normal               |   Milestone:  Never Assigned   
Component:  ofw - open firmware  |     Version:                   
 Keywords:                       |    Verified:  0                
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 Some USB disks take several seconds to become ready after a USB reset,
 resulting in "Failed to set device address" messages and inability to
 access the disk.

 This problem has been known for a long time, but left unfixed because we
 didn't want to increase the startup time.

 It turns out that there is a simple fix involving retrying the reset/set-
 address sequence with a delay.  If this is only applied after a failure
 has been seen, then the delay penalty does not affect faster-responding
 devices.

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Ticket URL: <https://dev.laptop.org/ticket/4501>
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