Reference: http://www.osronline.com/showthread.cfm?link=223812
In the above thread, Microsoft's Doron Holan (Windows driver expert) answered Microsoft's view on the perceived WinUSB limitations. I think this is of good reference to the list member here. Q1. WinUSB cannot be used to send an actual reset command to an USB device. A1: it is a privileged operation. Even if the user was an admin this can directly effect other stacks in a composite device". Q2: WinUSB cannot be used to set a device configuration that is different from the default one. A2: windows as a whole from a windows provided class driver pov only supports the default config Q3: WinUSB does not support multiple concurrent applications (as per the MSDN documenation). A3: correct. There is no way to know what is stateful and what is not. If you want concurrent app access, layer a umdf driver stack on winusb Q4: WinUSB does not support isochronous transfers. A4: yup. Neither does kmdf natively. The market for isoch support is extremely small, difficult to argue the cost benefit Q5: When using interface control requests (LIBUSB_RECIPIENT_INTERFACE), WinUSB overrides the low byte of wIndex with the destination interface. Ref: http://www.lvr.com/forum/index.php?topic=331 A5: this is so you only target your interface on a composite device. Letting a user mode stack manipulate a sibling interface is bad security and encapsulation, no? BTW, I have also posted this to libusb-win32 mailing list. -- Xiaofan ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ libusbx-devel mailing list libusbx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libusbx-devel
