xhci: Use soft retry to recover faster from transaction errors

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Use soft retry to recover from a USB Transaction Errors that are caused by
temporary error conditions. The USB device is not aware that the xHC
has halted the endpoint, and will be waiting for another retry

A Soft Retry perform additional retries and recover from an error which has
caused the xHC to halt an endpoint.

Soft retry has some limitations:
Soft Retry attempts shall not be performed on Isoch endpoints
Soft Retry attempts shall not be performed if the device is behind a TT in
a HS Hub

Software shall limit the number of unsuccessful Soft Retry attempts to
prevent an infinite loop.

For more details on Soft retry see xhci specs  4.6.8.1

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Mathias Nyman 2018-09-20 19:13:37 +03:00 • committed by Greg Kroah-Hartman

parent c94d41e9dd

commit f8f80be501

2 changed files with 21 additions and 0 deletions

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19

drivers/usb/host/xhci-ring.c

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2

drivers/usb/host/xhci.h

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