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 <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index 4dd39022c388..cddcda95b579 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/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.
          */