USB: gadget: Add ID numbers to configfs-gadget driver names

It is unable to use configfs to attach more than one gadget. When
attaching the second gadget, it always fails and the kernel message
prints out:

Error: Driver 'configfs-gadget' is already registered, aborting...
UDC core: g1: driver registration failed: -16

This commit fixes the problem by using the gadget name as a suffix
to each configfs_gadget's driver name, thus making the names
distinct.

Fixes: fc274c1e9973 ("USB: gadget: Add a new bus for gadgets")
Cc: stable <stable@kernel.org>
Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Link: https://lore.kernel.org/r/20230111065105.29205-1-chanh@os.amperecomputing.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 96121d1..0853536 100644 (file)
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -393,6 +393,7 @@ static void gadget_info_attr_release(struct config_item *item)
        WARN_ON(!list_empty(&gi->string_list));
        WARN_ON(!list_empty(&gi->available_func));
        kfree(gi->composite.gadget_driver.function);
+       kfree(gi->composite.gadget_driver.driver.name);
        kfree(gi);
 }
 
@@ -1572,7 +1573,6 @@ static const struct usb_gadget_driver configfs_driver_template = {
        .max_speed      = USB_SPEED_SUPER_PLUS,
        .driver = {
                .owner          = THIS_MODULE,
-               .name           = "configfs-gadget",
        },
        .match_existing_only = 1,
 };
@@ -1623,13 +1623,21 @@ static struct config_group *gadgets_make(
 
        gi->composite.gadget_driver = configfs_driver_template;
 
+       gi->composite.gadget_driver.driver.name = kasprintf(GFP_KERNEL,
+                                                           "configfs-gadget.%s", name);
+       if (!gi->composite.gadget_driver.driver.name)
+               goto err;
+
        gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
        gi->composite.name = gi->composite.gadget_driver.function;
 
        if (!gi->composite.gadget_driver.function)
-               goto err;
+               goto out_free_driver_name;
 
        return &gi->group;
+
+out_free_driver_name:
+       kfree(gi->composite.gadget_driver.driver.name);
 err:
        kfree(gi);
        return ERR_PTR(-ENOMEM);