On Wed, Sep 16, 2015 at 02:18:23PM -0700, Todd Efflam wrote: > Hello, > We have an issue where we cannot communicate with an old device with a > wMaxPacketSize set to 0xFFFF. It is visible using lsusb -v and shows > the correct max packte size, but is not listed in lsusb -t. The > dmesg output gives us "usb 2-2.1: Not enough bandwidth for new device > state. " and this comes from xhci (in particular xhci.c in the > xhci_configure_endpoint_result function). When we set the max packet > size on the device to something more reasonable (i.e. a0) the errors > go away and we are able to communicate with it. > > We would like to patch the xhci host driver to change any FFFF max > packet sizes to a0, but are having trouble finding where exactly to do > so. We've identified the function xhci_urb_enqueue as a possible > point, but printing out the max packet sizes (hw_max_packet_size and > max_packet_size) only shows sizes of 8. Unfortunately, changing the > configuration on the device itself is not an option. Any advice would > be appreciated! Can't you just fix the firmware on the broken device? I can't imagine it works on other operating systems properly as-is. thanks, greg k-h -- 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
