Commit 583ceada authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

USB: OHCI: fix root-hub resume bug 



When a suspended OHCI controller sees a port's status change, it sets
both the Root-Hub-Status-Change and the Resume-Detect bits in the
Interrupt Status register.  Processing both these bits, the driver
tries to resume the root hub twice!

This patch (as807) fixes the bug by ignoring RD if RHSC is set.  It
also prints a slightly more informative log message when a
remote-wakeup event occurs.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 51b5bce8

drivers/usb/host/ohci-hcd.c

+15 −10
Original line number Diff line number Diff line
@@ -715,13 +715,6 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd) 
		return IRQ_NOTMINE;

	}



	if (ints & OHCI_INTR_RHSC) {

		ohci_vdbg (ohci, "rhsc\n");

		ohci->next_statechange = jiffies + STATECHANGE_DELAY;

		ohci_writel (ohci, OHCI_INTR_RHSC, &regs->intrstatus);

		usb_hcd_poll_rh_status(hcd);

	}



	if (ints & OHCI_INTR_UE) {

		disable (ohci);

		ohci_err (ohci, "OHCI Unrecoverable Error, disabled\n");
@@ -731,7 +724,19 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd) 
		ohci_usb_reset (ohci);

	}



	if (ints & OHCI_INTR_RD) {

	if (ints & OHCI_INTR_RHSC) {

		ohci_vdbg(ohci, "rhsc\n");

		ohci->next_statechange = jiffies + STATECHANGE_DELAY;

		ohci_writel(ohci, OHCI_INTR_RD | OHCI_INTR_RHSC,

				&regs->intrstatus);

		usb_hcd_poll_rh_status(hcd);

	}



	/* For connect and disconnect events, we expect the controller

	 * to turn on RHSC along with RD.  But for remote wakeup events

	 * this might not happen.

	 */

	else if (ints & OHCI_INTR_RD) {

		ohci_vdbg(ohci, "resume detect\n");

		ohci_writel(ohci, OHCI_INTR_RD, &regs->intrstatus);

		hcd->poll_rh = 1;

drivers/usb/host/ohci-hub.c

+2 −1
Original line number Diff line number Diff line
@@ -169,7 +169,8 @@ __acquires(ohci->lock) 
		break;

	case OHCI_USB_RESUME:

		/* HCFS changes sometime after INTR_RD */

		ohci_info (ohci, "wakeup\n");

		ohci_info(ohci, "%swakeup\n",

				autostopped ? "auto-" : "");

		break;

	case OHCI_USB_OPER:

		/* this can happen after resuming a swsusp snapshot */

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