[Bug 214021] The USB devices fail to be detected during boot

[bugzilla-daemon@bugzilla.kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=214021

Mathias Nyman (mathias.nyman@linux.intel.com) changed:

           What    |Removed                     |Added
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                 CC|                            |mathias.nyman@linux.intel.c
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--- Comment #9 from Mathias Nyman (mathias.nyman@linux.intel.com) ---
Kishon reported this same issue.
xhci_alloc_dev()->xhci_queue_slot_control()->queue_command() fails because
xhci->xhc_state still had a  XHCI_STATE_HALTED bit set.

This is possible because the xhci driver will first add the high-speed
hcd/roothub, then the super-speed hcd/roothub.
xHC controller is started and xhci->xhc_state cleared only when the second,
super-speed hcd is added.

So if we are unlucky the first hs hcd will create the hs roothub device, 
hub driver binds to it, hub inits, and hub thread start enumerating devies
before xHC is running.

xHC port registers can be read when xHC is powered, before it's is running, so
hub thread is able to see the connected devices early.

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