usb-host-libusb: Configuration 0 may be a valid configuration

Quoting from: linux/Documentation/ABI/stable/sysfs-bus-usb:

	Note that some devices, in violation of the USB spec, have a
	configuration with a value equal to 0. Writing 0 to
	bConfigurationValue for these devices will install that
	configuration, rather then unconfigure the device.

So don't compare the configuration value against 0 to check for unconfigured
devices, instead check for a LIBUSB_ERROR_NOT_FOUND return from
libusb_get_active_config_descriptor().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Hans de Goede 2013-10-08 21:58:07 +02:00 committed by Gerd Hoffmann
parent 5af35d7fec
commit 1294ca797c
1 changed files with 4 additions and 5 deletions

View File

@ -992,15 +992,14 @@ static int usb_host_claim_interfaces(USBHostDevice *s, int configuration)
udev->ninterfaces = 0;
udev->configuration = 0;
if (configuration == 0) {
/* address state - ignore */
return USB_RET_SUCCESS;
}
usb_host_detach_kernel(s);
rc = libusb_get_active_config_descriptor(s->dev, &conf);
if (rc != 0) {
if (rc == LIBUSB_ERROR_NOT_FOUND) {
/* address state - ignore */
return USB_RET_SUCCESS;
}
return USB_RET_STALL;
}