commit e17a07a9e0b62d5a5f0a5683ecbabad3aa95a4d5

Author: Matthew Garrett <mjg@redhat.com>

Date:   Tue Jan 11 12:19:40 2011 -0500

    ehci: Check individual port status registers on resume

    If a device plug/unplug is detected on an ATI SB700 USB controller in D3,

    it appears to set the port status register but not the controller status

    register. As a result we'll fail to detect the plug event. Check the port

    status register on resume as well in order to catch this case.

    Signed-off-by: Matthew Garrett <mjg@redhat.com>

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c

index 796ea0c..d9c0748 100644

--- a/drivers/usb/host/ehci-hub.c

+++ b/drivers/usb/host/ehci-hub.c

@@ -106,6 +106,27 @@ static void ehci_handover_companion_ports(struct ehci_hcd *ehci)

 	ehci->owned_ports = 0;

 }

+static int ehci_port_change(struct ehci_hcd *ehci)

+{

+	int i = HCS_N_PORTS(ehci->hcs_params);

+

+	/* First check if the controller indicates a change event */

+

+	if (ehci_readl(ehci, &ehci->regs->status) & STS_PCD)

+		return 1;

+

+	/*

+	 * Not all controllers appear to update this while going from D3 to D0,

+	 * so check the individual port status registers as well

+	 */

+

+	while (i--)

+		if (ehci_readl(ehci, &ehci->regs->port_status[i]) & PORT_CSC)

+			return 1;

+

+	return 0;

+}

+

 static void ehci_adjust_port_wakeup_flags(struct ehci_hcd *ehci,

 		bool suspending, bool do_wakeup)

 {

@@ -168,7 +189,7 @@ static void ehci_adjust_port_wakeup_flags(struct ehci_hcd *ehci,

 	}

 	/* Does the root hub have a port wakeup pending? */

-	if (!suspending && (ehci_readl(ehci, &ehci->regs->status) & STS_PCD))

+	if (!suspending && ehci_port_change(ehci))

 		usb_hcd_resume_root_hub(ehci_to_hcd(ehci));

 	spin_unlock_irqrestore(&ehci->lock, flags);