USB: xhci: Notify the xHC when a device is reset.

When a USB device is reset, the xHCI hardware must know, in order to match
the device state and disable all endpoints except control endpoint 0.
Issue a Reset Device command after a USB device is successfully reset.
Wait on the command to finish, and then cache or free the disabled
endpoint rings.

There are four different USB device states that the xHCI hardware tracks:
 - disabled/enabled - device connection has just been detected,
 - default - the device has been reset and has an address of 0,
 - addressed - the device has a non-zero address but no configuration has
   been set,
 - configured - a set configuration succeeded.

The USB core may issue a port reset when a device is in any state, but the
Reset Device command will fail for a 0.96 xHC if the device is not in the
addressed or configured state.  Don't consider this failure as an error,
but don't free any endpoint rings if this command fails.

A storage driver may request that the USB device be reset during error
handling, so use GPF_NOIO instead of GPF_KERNEL while allocating memory
for the Reset Device command.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 20122ec75d94..feb0101f91eb 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1210,6 +1210,8 @@ void xhci_dbg_erst(struct xhci_hcd *xhci, struct xhci_erst *erst);
 void xhci_dbg_cmd_ptrs(struct xhci_hcd *xhci);
 void xhci_dbg_ring_ptrs(struct xhci_hcd *xhci, struct xhci_ring *ring);
 void xhci_dbg_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx, unsigned int last_ep);
+inline char *xhci_get_slot_state(struct xhci_hcd *xhci,
+                struct xhci_container_ctx *ctx);
 
 /* xHCI memory management */
 void xhci_mem_cleanup(struct xhci_hcd *xhci);
@@ -1298,6 +1300,7 @@ int xhci_queue_evaluate_context(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
                 u32 slot_id);
 int xhci_queue_reset_ep(struct xhci_hcd *xhci, int slot_id,
                 unsigned int ep_index);
+int xhci_queue_reset_device(struct xhci_hcd *xhci, u32 slot_id);
 void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
                 unsigned int slot_id, unsigned int ep_index,
                 struct xhci_td *cur_td, struct xhci_dequeue_state *state);