Hi. I've been trying to examine the operation of a USB device by snooping on it while it's running with its proprietary driver in a VirtualBox (closed source, PUEL edition, so no trickery on my part to get USB working) running Windows XP. When the device is connected and on, the kernel starts spamming: usb 1-1: bogus endpoint ep1in in usb_submit_urb (bad maxpacket 0) usb 1-1: usbfs: usb_submit_urb returned -90 continuously, without end. Examining the function usb_submit_urb in drivers/usb/core/urb.c of the kernel source tree (2.6.30) indicates that the issue is with a wMaxPacketSize descriptor equal to zero. Examining the descriptor tree of my device confirms that for the given interface, bAlternateSetting = 0, there is an endpoint 0x81 (otherwise reported in the error message as ep1in) for which wMaxPacketSize is zero. (Find the complete descriptor tree `lsusb -d 05a9:a538 -v` at http://pastebin.ca/1616649 ). For the same interface, there is also an alternate bAlternateSetting = 1 for which there is an endpoint 0x81 with wMaxPacketSize = 0x13fc (3x 1020 bytes). Now, at this juncture I am not familiar enough with standard USB operation to know what to expect from Alternate Settings on a given Interface. So as I read up on the standards, I appeal before the gods of linux-usb: is such a device with wMaxPacketSize = 0x00 simply insane? Is there some easy, or otherwise, way I could force the device to use bAlternateSetting = 0, just for the hell of it? The device does appear to "just work" under a system booted into Windows (no virtualization), and in the meantime I'll try to snoop around there, if possible. I suppose I haven't given much information to work with here, but again, any insight on sanity of the device would be appreciated. Thanks. Tim -- 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
