fix USB devices with multiple configurations
This patch fixes bugs in usbdcore*.c related to the use of devices
with multiple configurations.
The original code made mistakes about the meaning of configuration value and
configuration index, and the resulting off-by-one errors resulted in:
* SET_CONFIGURATION always selected the first configuration, no matter what
wValue is being passed.
* GET_DESCRIPTOR/CONFIGURATION always returned the descriptor for the first
configuration (index 0).
Signed-off-by: Harald Welte <laforge@openmoko.org>
Acked-by: Markus Klotzbuecher <mk@denx.de>
diff --git a/drivers/usb/usbdcore.c b/drivers/usb/usbdcore.c
index 308c7ce..a621ce7 100644
--- a/drivers/usb/usbdcore.c
+++ b/drivers/usb/usbdcore.c
@@ -146,12 +146,9 @@
static struct usb_configuration_instance *usbd_device_configuration_instance (struct usb_device_instance *device,
unsigned int port, unsigned int configuration)
{
- /* XXX */
- configuration = configuration ? configuration - 1 : 0;
-
- if (configuration >= device->configurations) {
+ if (configuration >= device->configurations)
return NULL;
- }
+
return device->configuration_instance_array + configuration;
}