USB: EHCI: log a warning if ehci-hcd is not loaded first

This patch (as1139) adds a warning to the system log whenever ehci-hcd
is loaded after ohci-hcd or uhci-hcd.  Nowadays most distributions are
pretty good about not doing this; maybe the warning will help convince
anyone still doing it wrong.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>  [2.6.27]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 10 insertions, 0 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index c8035a8216bd..fc9018e72a09 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -81,6 +81,10 @@
 
 /*-------------------------------------------------------------------------*/
 
+/* Keep track of which host controller drivers are loaded */
+unsigned long usb_hcds_loaded;
+EXPORT_SYMBOL_GPL(usb_hcds_loaded);
+
 /* host controllers we manage */
 LIST_HEAD (usb_bus_list);
 EXPORT_SYMBOL_GPL (usb_bus_list);
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index e710ce04e228..2dcde61c465e 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -482,4 +482,10 @@ static inline void usbmon_urb_complete(struct usb_bus *bus, struct urb *urb,
  */
 extern struct rw_semaphore ehci_cf_port_reset_rwsem;
 
+/* Keep track of which host controller drivers are loaded */
+#define USB_UHCI_LOADED         0
+#define USB_OHCI_LOADED         1
+#define USB_EHCI_LOADED         2
+extern unsigned long usb_hcds_loaded;
+
 #endif /* __KERNEL__ */