USB_DEVICE_QUALIFIER_DESCRIPTOR - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// usbspec.h
typedef struct _USB_DEVICE_QUALIFIER_DESCRIPTOR {
UCHAR bLength;
UCHAR bDescriptorType;
USHORT bcdUSB;
UCHAR bDeviceClass;
UCHAR bDeviceSubClass;
UCHAR bDeviceProtocol;
UCHAR bMaxPacketSize0;
UCHAR bNumConfigurations;
UCHAR bReserved;
} USB_DEVICE_QUALIFIER_DESCRIPTOR, *PUSB_DEVICE_QUALIFIER_DESCRIPTOR;
View the official Windows Driver Kit DDI referenceNo description available.
The USB_DEVICE_QUALIFIER_DESCRIPTOR structure is used by USB client drivers to retrieve a USB-defined device qualifier descriptor.
bLengthSpecifies the length, in bytes, of this descriptor.
bDescriptorTypeSpecifies the descriptor type. Must be set to USB_DEVICE_QUALIFIER_DESCRIPTOR_TYPE.
bcdUSBIdentifies the version of the USB specification that this descriptor structure complies with. This value is a binary-coded decimal number.
bDeviceClassSpecifies the class code of the device as assigned by the USB specification group.
bDeviceSubClassSpecifies the subclass code of the device as assigned by the USB specification group.
bDeviceProtocolSpecifies the protocol code of the device as assigned by the USB specification group.
bMaxPacketSize0Specifies the maximum packet size, in bytes, for endpoint zero of the device. The value must be set to 8, 16, 32, or 64.
bNumConfigurationsSpecifies the total number of possible configurations for the device.
bReservedReserved.
This structure is similar to USB_DEVICE_DESCRIPTOR, but it contains only those members that can change when the device switches from full-speed operation to high-speed operation or vice versa. If the device is operating at full speed, querying for this descriptor will contain information about how the device would operate at high-speed. If, on the other hand, the device is operating at high-speed, this descriptor will contain information about how the device would operate at full-speed.
_URB_CONTROL_DESCRIPTOR_REQUEST