[patch 12/17] USB: EHCI: log a warning if ehci-hcd is not loadedfirst

From: Greg KH
Date: Sat Oct 18 2008 - 15:07:50 EST


2.6.27-stable review patch. If anyone has any objections, please let us
know.

------------------
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

commit 9beeee6584b9aa4f9192055512411484a2a624df upstream

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@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/usb/core/hcd.c | 4 ++++
drivers/usb/core/hcd.h | 6 ++++++
drivers/usb/host/ehci-hcd.c | 15 +++++++++++++--
drivers/usb/host/ohci-hcd.c | 3 +++
drivers/usb/host/uhci-hcd.c | 3 +++
5 files changed, 29 insertions(+), 2 deletions(-)

--- 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);
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -482,4 +482,10 @@ static inline void usbmon_urb_complete(s
*/
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__ */
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -1049,6 +1049,12 @@ static int __init ehci_hcd_init(void)
{
int retval = 0;

+ set_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
+ if (test_bit(USB_UHCI_LOADED, &usb_hcds_loaded) ||
+ test_bit(USB_OHCI_LOADED, &usb_hcds_loaded))
+ printk(KERN_WARNING "Warning! ehci_hcd should always be loaded"
+ " before uhci_hcd and ohci_hcd, not after\n");
+
pr_debug("%s: block sizes: qh %Zd qtd %Zd itd %Zd sitd %Zd\n",
hcd_name,
sizeof(struct ehci_qh), sizeof(struct ehci_qtd),
@@ -1056,8 +1062,10 @@ static int __init ehci_hcd_init(void)

#ifdef DEBUG
ehci_debug_root = debugfs_create_dir("ehci", NULL);
- if (!ehci_debug_root)
- return -ENOENT;
+ if (!ehci_debug_root) {
+ retval = -ENOENT;
+ goto err_debug;
+ }
#endif

#ifdef PLATFORM_DRIVER
@@ -1104,7 +1112,9 @@ clean0:
#ifdef DEBUG
debugfs_remove(ehci_debug_root);
ehci_debug_root = NULL;
+err_debug:
#endif
+ clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
return retval;
}
module_init(ehci_hcd_init);
@@ -1126,6 +1136,7 @@ static void __exit ehci_hcd_cleanup(void
#ifdef DEBUG
debugfs_remove(ehci_debug_root);
#endif
+ clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
}
module_exit(ehci_hcd_cleanup);

--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -1098,6 +1098,7 @@ static int __init ohci_hcd_mod_init(void
printk (KERN_DEBUG "%s: " DRIVER_INFO "\n", hcd_name);
pr_debug ("%s: block sizes: ed %Zd td %Zd\n", hcd_name,
sizeof (struct ed), sizeof (struct td));
+ set_bit(USB_OHCI_LOADED, &usb_hcds_loaded);

#ifdef DEBUG
ohci_debug_root = debugfs_create_dir("ohci", NULL);
@@ -1184,6 +1185,7 @@ static int __init ohci_hcd_mod_init(void
error_debug:
#endif

+ clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
return retval;
}
module_init(ohci_hcd_mod_init);
@@ -1214,6 +1216,7 @@ static void __exit ohci_hcd_mod_exit(voi
#ifdef DEBUG
debugfs_remove(ohci_debug_root);
#endif
+ clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
}
module_exit(ohci_hcd_mod_exit);

--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -953,6 +953,7 @@ static int __init uhci_hcd_init(void)

printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "%s\n",
ignore_oc ? ", overcurrent ignored" : "");
+ set_bit(USB_UHCI_LOADED, &usb_hcds_loaded);

if (usb_disabled())
return -ENODEV;
@@ -988,6 +989,7 @@ debug_failed:

errbuf_failed:

+ clear_bit(USB_UHCI_LOADED, &usb_hcds_loaded);
return retval;
}

@@ -997,6 +999,7 @@ static void __exit uhci_hcd_cleanup(void
kmem_cache_destroy(uhci_up_cachep);
debugfs_remove(uhci_debugfs_root);
kfree(errbuf);
+ clear_bit(USB_UHCI_LOADED, &usb_hcds_loaded);
}

module_init(uhci_hcd_init);

--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/