From: Alan Stern <stern@rowland.harvard.edu>
Date: Fri, 19 Oct 2007 13:51:58 +0000 (-0400)
Subject: USB: fix interface sysfs file-creation bug
X-Git-Tag: firefly_0821_release~24602^2~12
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=439a903a9663c0caa8094f3907ca60069d6c36e7;p=firefly-linux-kernel-4.4.55.git

USB: fix interface sysfs file-creation bug

This patch (as1005) fixes a rather subtle problem.  When
usb_set_configuration() registers the interfaces and their files in
sysfs, it doesn't expect those files to exist already.  But when an
interface is registered, its driver may call usb_set_interface() and
thereby cause the sysfs files to be created.  The result is an error
when usb_set_configuration() goes on to create those same files again.

The (not-so-great) solution is to have usb_set_configuration() remove
any existing files before creating them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 8bdaa157ffe7..eb4ac47612a5 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1641,7 +1641,13 @@ free_interfaces:
 				intf->dev.bus_id, ret);
 			continue;
 		}
-		usb_create_sysfs_intf_files (intf);
+
+		/* The driver's probe method can call usb_set_interface(),
+		 * which would mean the interface's sysfs files are already
+		 * created.  Just in case, we'll remove them first.
+		 */
+		usb_remove_sysfs_intf_files(intf);
+		usb_create_sysfs_intf_files(intf);
 	}
 
 	usb_autosuspend_device(dev);