[Nut-upsdev] ETIME on FreeBSD

[Alexey Loukianov]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

17.01.2010 06:54, Charles Lepple wrote:
>
> I guess I'm curious as to the source of that error code - I didn't see
> it in libusb, so is it coming from the Linux kernel?
>

Yes, it happen to come from the linux kernel and its meaning in our case is
"ioctl URB operation timed out". ETIME is defined in
/usr/include/asm-generic/errno.h, and this file is from kernel-headers package.

The code that triggered this compilation error on freebsd was added by Arjen as
a possible measure to 'heal' stalled Ippon USB device. Details of our
conversation concerning NUT compatibility with Ippon UPSes are available on
maillist archives. The story in short is that Ippon usb-to-serial devices are
totally buggy and happen to hang every time the data wasn't read back in 64
bytes chunk. In case the device had hanged the only two ways to reboot it is to
either replug the cable or to do USB port reset. Linux error code returned when
communicating with the stalled device is ETIME (btw., I beleive that is should
be "-ETIME" in NUT code instead of "ETIME"). So, Arjen had implemented special
recovery handler for this error condition.

This changes are still work-in-progress as there are pitfalls when reseting usb
device (device handle should be re-opened, bus should be re-enumerated and it is
unclear from libusb docs if it is required or not to do usb_close() on old usb
device handle after usb_reset() call) and I hadn't had enough time to test
Arjen's modifications on the Ippon device I had access to. Now it looks like I
also will have to install FreeBSD on my notebook in order to check if it is
possible to reset usb device using FreeBSD's implementation of libusb and to
determine the error code that is returned for stalled device under FreeBSD.

> The reason is that we try to add autoconf tests for definitions like
> this, and it's good to have something more general than just "is ETIME
> defined?"
>

I don't think there's a need for separate autoconf definition for ETIME as this
error code seems to be linux-specific and platform type is the thing that happen
to be checked up automatically by autoconf.

- -- 
Best regards,
Alexey Loukianov                          mailto:mooroon2 at mail.ru
System Engineer,                            Mob.:+7(926)218-1320
*nix Specialist

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iQEcBAEBAgAGBQJLUpAkAAoJEPB9BOdTkBULhqkH/1A9nrhbwEUYX3B4lqrxIzJs
1bzNJXbGNwKrwt3bcI06EAj3UMQn45Ehhb89VbC51GGmj+8kFJGG0sU2aeilXhuu
sw6AxJrXTnzDsBiivTEvJQqkWf+tKgVrUvi749vJDiByF6Alx1FgoAPAsruTkt+r
tXxLlrqHLBNHYJvGdJCR1wpqnIG4kuIl9ggAI1EYIhKWAUuJ68diHExlGWTpX9AN
oi4hDF89tk3J+DlysnMolqJ0luXvRKFgsuyZwWgJcqW8uVNb5KOgh/Ijpg6pTSTR
e70dfWySNgjxE5vbkcHyIphufM7qnWD5RDKSn4GkKDDSC01oA0oOSqR9jsY5qbs=
=cJvr
-----END PGP SIGNATURE-----