xhci: Tell USB core both roothubs lost power.

On a resume, when the power is lost during hibernate, the USB core will
call hub_reset_resume for the xHCI USB 2.0 roothub, but not for the USB
3.0 roothub:

[  164.748310] usb usb1: root hub lost power or was reset
[  164.748353] usb usb2: root hub lost power or was reset
[  164.748487] usb usb3: root hub lost power or was reset
[  164.748488] xhci_hcd 0000:01:00.0: Stop HCD
...
[  164.870039] hub 4-0:1.0: hub_resume
...
[  164.870054] hub 3-0:1.0: hub_reset_resume

This causes issues later, because the USB core assumes the USB 3.0 hub
attached to the USB 3.0 roothub is still active.  It attempts to queue a
control URB for the external hub, which fails because all the device
slot contexts were released when the USB 3.0 roothub lost power:

[  164.980044] hub 4-1:1.0: hub_resume
[  164.980047] xhci_hcd 0000:01:00.0: Get port status returned 0x10101
[  164.980049] xHCI xhci_urb_enqueue called with unaddressed device
[  164.980053] hub 3-0:1.0: port 1: status 0101 change 0001
[  164.980056] hub 4-1:1.0: hub_port_status failed (err = -22)
[  164.980060] xhci_hcd 0000:01:00.0: `MEM_WRITE_DWORD(3'b000, 32'hffffc90008948440, 32'h202e1, 4'hf);
[  164.980062] xHCI xhci_urb_enqueue called with unaddressed device
[  164.980066] xhci_hcd 0000:01:00.0: clear port connect change, actual port 0 status  = 0x2e1
[  164.980069] hub 4-1:1.0: hub_port_status failed (err = -22)
[  164.980072] xhci_hcd 0000:01:00.0: get port status, actual port 1 status  = 0x2a0
[  164.980074] xHCI xhci_urb_enqueue called with unaddressed device
[  164.980077] xhci_hcd 0000:01:00.0: Get port status returned 0x100
[  164.980079] hub 4-1:1.0: hub_port_status failed (err = -22)
[  164.980082] xHCI xhci_urb_enqueue called with unaddressed device
[  164.980085] hub 4-1:1.0: hub_port_status failed (err = -22)
[  164.980088] hub 4-1:1.0: port 4: status 0000 change 0000
[  164.980091] xHCI xhci_urb_enqueue called with unaddressed device
[  164.980094] hub 4-1:1.0: activate --> -22
[  164.980113] xHCI xhci_urb_enqueue called with unaddressed device
[  164.980117] hub 4-1:1.0: hub_port_status failed (err = -22)
[  164.980119] xHCI xhci_urb_enqueue called with unaddressed device
[  164.980123] hub 4-1:1.0: can't resume port 4, status -22
[  164.980126] hub 4-1:1.0: port 4 status ffff.ffff after resume, -22
[  164.980129] usb 4-1.4: can't resume, status -22
[  164.980131] hub 4-1:1.0: logical disconnect on port 4

This causes issues when a USB 3.0 hard drive is attached to the external
USB 3.0 hub when the system is hibernated:

[ 6249.849653] sd 8:0:0:0: [sdb] Unhandled error code
[ 6249.849659] sd 8:0:0:0: [sdb]  Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
[ 6249.849663] sd 8:0:0:0: [sdb] CDB: Read(10): 28 00 00 00 2a 08 00 00 02 00
[ 6249.849671] end_request: I/O error, dev sdb, sector 10760

Make sure to inform the USB core that *both* xHCI roothubs lost power.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/host/xhci.c

@@ -771,7 +771,9 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 
 	/* If restore operation fails, re-initialize the HC during resume */
 	if ((temp & STS_SRE) || hibernated) {
-		usb_root_hub_lost_power(hcd->self.root_hub);
+		/* Let the USB core know _both_ roothubs lost power. */
+		usb_root_hub_lost_power(xhci->main_hcd->self.root_hub);
+		usb_root_hub_lost_power(xhci->shared_hcd->self.root_hub);
 
 		xhci_dbg(xhci, "Stop HCD\n");
 		xhci_halt(xhci);