xhci: Avoid USB autosuspend when resuming USB2 ports.

When USB bus host controller root hub resumes from autosuspend,
it immediately tries to enter auto-suspend, but there can be a
scenario when root hub is resuming its usb2 ports, in that particular
case USB host controller auto suspend fails since it is busy
to resuming its usb2 ports.

This makes multiple failed cycles of auto-suspend until all usb2
ports of host controller root hub do not resume.

This patch uses USB core framework usb_hcd_start_port_resume,
usb_hcd_end_port_resume API's in order to  autoresume/autosuspend
root hub properly.

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

drivers/usb/host/xhci-hub.c

@@ -900,6 +900,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
 				set_bit(wIndex, &bus_state->resuming_ports);
 				bus_state->resume_done[wIndex] = timeout;
 				mod_timer(&hcd->rh_timer, timeout);
+				usb_hcd_start_port_resume(&hcd->self, wIndex);
 			}
 		/* Has resume been signalled for USB_RESUME_TIME yet? */
 		} else if (time_after_eq(jiffies,
@@ -940,6 +941,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
 				clear_bit(wIndex, &bus_state->rexit_ports);
 			}
 
+			usb_hcd_end_port_resume(&hcd->self, wIndex);
 			bus_state->port_c_suspend |= 1 << wIndex;
 			bus_state->suspended_ports &= ~(1 << wIndex);
 		} else {
@@ -962,6 +964,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
 	    (raw_port_status & PORT_PLS_MASK) != XDEV_RESUME) {
 		bus_state->resume_done[wIndex] = 0;
 		clear_bit(wIndex, &bus_state->resuming_ports);
+		usb_hcd_end_port_resume(&hcd->self, wIndex);
 	}
 
 
@@ -1337,6 +1340,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 					goto error;
 
 				set_bit(wIndex, &bus_state->resuming_ports);
+				usb_hcd_start_port_resume(&hcd->self, wIndex);
 				xhci_set_link_state(xhci, ports[wIndex],
 						    XDEV_RESUME);
 				spin_unlock_irqrestore(&xhci->lock, flags);
@@ -1345,6 +1349,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				xhci_set_link_state(xhci, ports[wIndex],
 							XDEV_U0);
 				clear_bit(wIndex, &bus_state->resuming_ports);
+				usb_hcd_end_port_resume(&hcd->self, wIndex);
 			}
 			bus_state->port_c_suspend |= 1 << wIndex;
 

drivers/usb/host/xhci-ring.c

@@ -1606,6 +1606,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
 			set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 			mod_timer(&hcd->rh_timer,
 				  bus_state->resume_done[hcd_portnum]);
+			usb_hcd_start_port_resume(&hcd->self, hcd_portnum);
 			bogus_port_status = true;
 		}
 	}