USB: unconfigure devices which have config 0
Some USB devices do have a configuration 0, in contravention of the
USB spec. Normally 0 is supposed to indicate that a device is
unconfigured.
While we can't change what the device is doing, we can change usbcore.
This patch (as852) allows usb_set_configuration() to accept a config
value of -1 as indicating that the device should be unconfigured. The
request actually sent to the device will still contain 0 as the value.
But even if the device does have a configuration 0, dev->actconfig
will be set to NULL and dev->state will be set to USB_STATE_ADDRESS.
Without some sort of special-case handling like this, there is no way
to unconfigure these non-compliant devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 2087766..274f14f 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -857,11 +857,11 @@
static int proc_setconfig(struct dev_state *ps, void __user *arg)
{
- unsigned int u;
+ int u;
int status = 0;
struct usb_host_config *actconfig;
- if (get_user(u, (unsigned int __user *)arg))
+ if (get_user(u, (int __user *)arg))
return -EFAULT;
actconfig = ps->dev->actconfig;