[3.16.y-ckt stable] Patch "xhci: refuse loading if nousb is used" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    xhci: refuse loading if nousb is used

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt24.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From fa25f0e64eec10217e6802b44c1824cd91b7b1c7 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum at suse.com>
Date: Thu, 3 Dec 2015 15:03:34 +0100
Subject: xhci: refuse loading if nousb is used

commit 1eaf35e4dd592c59041bc1ed3248c46326da1f5f upstream.

The module should fail to load.

Signed-off-by: Oliver Neukum <oneukum at suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
[ luis: backported to 3.16:
  - moved usb_disabled() check to the top of the function so that there's
    no need to invoke xhci_unregister_pci() before returning.  Suggested
    by gregkh. ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/host/xhci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 20209e870a99..d9dd9264f813 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4928,6 +4928,9 @@ static int __init xhci_hcd_init(void)
 {
 	int retval;

+	if (usb_disabled())
+		return -ENODEV;
+
 	retval = xhci_register_pci();
 	if (retval < 0) {
 		pr_debug("Problem registering PCI driver.\n");
@@ -4955,6 +4958,7 @@ static int __init xhci_hcd_init(void)
 	BUILD_BUG_ON(sizeof(struct xhci_intr_reg) != 8*32/8);
 	/* xhci_run_regs has eight fields and embeds 128 xhci_intr_regs */
 	BUILD_BUG_ON(sizeof(struct xhci_run_regs) != (8+8*128)*32/8);
+
 	return 0;
 unreg_pci:
 	xhci_unregister_pci();