From 89ccbdc91bc5a433fa256c0136fbe181d7c5d474 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Sun, 2 Apr 2006 10:18:09 -0800 Subject: [PATCH] [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: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/Kconfig | 7 +++++++ drivers/usb/core/hub.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig index ff03184da40..a08787e253a 100644 --- a/drivers/usb/core/Kconfig +++ b/drivers/usb/core/Kconfig @@ -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. diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 3c76f7e17c0..0c87f73f293 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -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) && -- 2.20.1