On Thu, Jun 06, 2019 at 03:19:14PM +0000, Bollinger, Seth wrote: > > On Jun 6, 2019, at 10:03 AM, Alan Stern <st...@rowland.harvard.edu> wrote: > > > > EPERM means that the file descriptor was not opened with write access. > > It has nothing to do with reset failures. > > Yes, I was confused by that as well so spent some time instrumenting the > kernel. It definitely is open for writing, and get’s by the initial f_mode > check in devio.c:usbdev_do_ioctl. > > Is it possibly a default error that’s returned when some deeper error is > encountered? Unfortunately I was unable to determine exactly where it was > coming from...
ftrace is your friend :)
