USB: controller resume should check the root hub

This patch (as1394) adds code to ehci-hcd, ohci-hcd, and uhci-hcd for
automatically resuming the root hub when the controller is resumed, if
the root hub has a wakeup request pending on some port.

During resume from system sleep this doesn't matter, because the root
hubs will naturally be resumed along with every other device in the
system.  However it _will_ matter for runtime PM: If the controller is
suspended and a remote wakeup request is received then the controller
will autoresume, but we need to ensure that the root hub also
autoresumes.  Otherwise the wakeup request would be ignored, the
controller would go back to sleep, and the cycle would repeat a large
number of times (I saw this happen before the patch was written).

Signed-off-by: Alan Stern <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: AlanStern

drivers/usb/host/ehci-hub.c

@@ -166,6 +166,10 @@ static void ehci_adjust_port_wakeup_flags(struct ehci_hcd *ehci,
 			ehci_writel(ehci, temp | HOSTPC_PHCD, hostpc_reg);
 		}
 	}
+
+	/* Does the root hub have a port wakeup pending? */
+	if (!suspending && (ehci_readl(ehci, &ehci->regs->status) & STS_PCD))
+		usb_hcd_resume_root_hub(ehci_to_hcd(ehci));
 }
 
 static int ehci_bus_suspend (struct usb_hcd *hcd)

drivers/usb/host/ohci-hub.c

@@ -355,6 +355,11 @@ static void ohci_finish_controller_resume(struct usb_hcd *hcd)
 		ohci_readl(ohci, &ohci->regs->intrenable);
 		msleep(20);
 	}
+
+	/* Does the root hub have a port wakeup pending? */
+	if (ohci_readl(ohci, &ohci->regs->intrstatus) &
+			(OHCI_INTR_RD | OHCI_INTR_RHSC))
+		usb_hcd_resume_root_hub(hcd);
 }
 
 /* Carry out polling-, autostop-, and autoresume-related state changes */
@@ -364,7 +369,7 @@ static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
 	int	poll_rh = 1;
 	int	rhsc_enable;
 
-	/* Some broken controllers never turn off RHCS in the interrupt
+	/* Some broken controllers never turn off RHSC in the interrupt
 	 * status register.  For their sake we won't re-enable RHSC
 	 * interrupts if the interrupt bit is already active.
 	 */

drivers/usb/host/uhci-hcd.c

@@ -862,10 +862,11 @@ static int uhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 	/* If interrupts don't work and remote wakeup is enabled then
 	 * the suspended root hub needs to be polled.
 	 */
-	if (!uhci->RD_enable && hcd->self.root_hub->do_remote_wakeup) {
+	if (!uhci->RD_enable && hcd->self.root_hub->do_remote_wakeup)
 		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
-		usb_hcd_poll_rh_status(hcd);
-	}
+
+	/* Does the root hub have a port wakeup pending? */
+	usb_hcd_poll_rh_status(hcd);
 	return 0;
 }
 #endif

drivers/usb/host/uhci-hub.c

@@ -200,7 +200,7 @@ static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
 	    case UHCI_RH_SUSPENDING:
 	    case UHCI_RH_SUSPENDED:
 		/* if port change, ask to be resumed */
-		if (status)
+		if (status || uhci->resuming_ports)
 			usb_hcd_resume_root_hub(hcd);
 		break;