xhci: Restore event ring dequeue pointer on resume.

BugLink: http://bugs.launchpad.net/bugs/987337

commit fb3d85bc7193f23c9a564502df95564c49a32c91 upstream.

The xhci_save_registers() function saved the event ring dequeue pointer
in the s3 register structure, but xhci_restore_registers() never
restored it.  No other code in the xHCI successful resume path would
ever restore it either.  Fix that.

This should be backported to kernels as old as 2.6.37, that contain the
commit 5535b1d5f8885695c6ded783c692e3c0d0eda8ca "USB: xHCI: PCI power
management implementation".

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Elric Fu <elricfu1@gmail.com>
Cc: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f0b76f0..0f92504 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -681,6 +681,7 @@ static void xhci_restore_registers(struct xhci_hcd *xhci)
        xhci_writel(xhci, xhci->s3.irq_control, &xhci->ir_set->irq_control);
        xhci_writel(xhci, xhci->s3.erst_size, &xhci->ir_set->erst_size);
        xhci_write_64(xhci, xhci->s3.erst_base, &xhci->ir_set->erst_base);
+       xhci_write_64(xhci, xhci->s3.erst_dequeue, &xhci->ir_set->erst_dequeue);
 }
 
 static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci)