Hello Alan. > Plenty of things could affect it. Without knowing more about your system, I can't be more specific. For example, what UDC > driver are you using? Ah 😊. It's an ancient (3.4.x*) sunxi_usb_hdc running on an AllWinner H3. > And have you tried testing your program with the dummy-hcd driver? Good point. Not yet. > Do you get the correct values for the GADGETFS_SETUP event? You mean post enumeration from host to device? Yes, I send some majik packets for proof of life. All good in that direction. > What is the return value from the write() call where you send the vendor data? As expected, the number of bytes written back to the endpoint. In this case 4. > If you want to add some debugging output to the kernel's gadgetfs driver, the appropriate place would be inside epo_write() in drivers/usb/gadget/legacy/inode.c. The part following: Ideal and once again extremely helpful. Thank you. BR, Jerry. * We will move to mainline ASAP but this is a quick proof of concept and there is zero support in mainline for the essential AllWinner camera interface. That'll be the next task. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
