Hi Tim, On 15-Aug-13 20:24, Tim Roberts wrote:
>> What do you mean by "You don't need the IAD"? Do you mean >> you do not need to parse the IAD descriptors? > > Right. The IAD is a simple descriptor. It only provides two things: > the class/subclass/protocol for the interface group, and the interface > numbers that are part of the group. You don't need the interface > numbers, because the rewritten configuration descriptor only includes > those interfaces. You don't need the class/subclass/protocol, because > if you have a class-generic driver, usbccgp.sys will have created a > generic PDO for the class/subclass. If you have a device-specific > driver, then you know what the class and subclass are. I wonder if this fully applies from the libusbx point of view. My understanding of its interface (but please mind my so far limited experience with the library) was that it enumerates really the "physical" devices, even if composite. I.e. the composite device is still enumerated as single device with multiple interfaces rather than multiple devices "invented" by usbccgp.sys. Am I wrong? Also, the config descriptor seems to be queried through the parent hub's driver using IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION thus bypassing usbccgp.sys or any other driver associated with the composite parent. I assume if the above observation is correct, the config descriptor, as seen by libusbx wouldn't be modified - but I don't have currently around any suitable device for verification. Jan ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite! It's a free troubleshooting tool designed for production. Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk _______________________________________________ libusbx-devel mailing list libusbx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libusbx-devel
