Commit 89ccbdc9 authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman

[PATCH] USB: otg hub support is optional

USB OTG devices are not required to support external hubs.  This adds a
configuration option to disable that support.
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4d45e218
......@@ -99,4 +99,11 @@ config USB_OTG_WHITELIST
normal Linux-USB hosts do (other than the warning), and is
convenient for many stages of product development.
config USB_OTG_BLACKLIST_HUB
bool "Disable external hubs"
depends on USB_OTG
help
If you say Y here, then Linux will refuse to enumerate
external hubs. OTG hosts are allowed to reduce hardware
and software costs by not supporting external hubs.
......@@ -836,6 +836,13 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
desc = intf->cur_altsetting;
hdev = interface_to_usbdev(intf);
#ifdef CONFIG_USB_OTG_BLACKLIST_HUB
if (hdev->parent) {
dev_warn(&intf->dev, "ignoring external hub\n");
return -ENODEV;
}
#endif
/* Some hubs have a subclass of 1, which AFAICT according to the */
/* specs is not defined, but it works */
if ((desc->desc.bInterfaceSubClass != 0) &&
......
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