[PATCH v4 0/5] usb: xhci: Handle USB transaction error on address command

[Lu Baolu]

Xhci driver handles USB transaction errors on transfer events,
but transaction errors are possible on address device command
completion events as well.

The xHCI specification (section 4.6.5) says: A USB Transaction
Error Completion Code for an Address Device Command may be due
to a Stall response from a device. Software should issue a Disable
Slot Command for the Device Slot then an Enable Slot Command to
recover from this error.

The related discussion threads can be found through below links.

http://marc.info/?l=linux-usb&m=149362010728921&w=2
http://marc.info/?l=linux-usb&m=149252752825755&w=2

This patch set includes some fixes in xhci_disable_slot() as well
which will be used to handle USB transaction error on address
command.

---
Change log:

v1->v2:
 - Add 4 fixes in xhci_disable_slot which will be used
   to handle USB transaction error on address command.

v2->v3:
 - Add checking virt dev for test mode in PATCH 1/5.

v3->v4:
 - Resolve xhci->mutex locking issue in 5/5.

Lu Baolu (5):
  usb: xhci: Disable slot even virt-dev is null
  usb: xhci: Fix potential memory leak in xhci_disable_slot()
  usb: xhci: Fix memory leak when xhci_disable_slot() returns error
  usb: xhci: Return error when host is dead in xhci_disable_slot()
  usb: xhci: Handle USB transaction error on address command

 drivers/usb/host/xhci-hub.c |  5 ++++-
 drivers/usb/host/xhci.c     | 54 +++++++++++++++++++--------------------------
 drivers/usb/host/xhci.h     |  3 +--
 3 files changed, 28 insertions(+), 34 deletions(-)

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2.7.4