On 2 June 2014 18:42, Kalle Valo [off-list ref] wrote:

Bartosz Markowski [off-list ref] writes:

quoted

Firmware 10.x supports up to 8 virtual AP interfaces
(comparing to 7 for main firmware). Previous vdev map
initialization was missing enough space for 8 + 1 vdevs
(we may spent one for mac monitor), due to wrong define used.

Use correct one - TARGET_10X_NUM_VDEVS - for 10.x firmware.

Signed-off-by: Bartosz Markowski <redacted>

So what is the actual bug you are fixing? Previously with 10.x it was
possible to get only 7 VIFs, even though we advertised 8 to user space,
and with your fix we get the full 8 VIFs?

For CAC, we use one VDEV to start monitor interface. In case of 10.X
firmware we advertise support up to 8 VAPs, but if we spent one for
monitor interface, only 7 left. I've noticed we fail on .add_interface
when trying to add 8th AP, here:

    bit = ffs(ar->free_vdev_map);
    if (bit == 0) {
        ret = -EBUSY;
        goto err;
    }

and this lead me to initialization code for vdev_map

    ar->free_vdev_map = (1 << TARGET_NUM_VDEVS) - 1;

We have an API split for main and 10.x firmware (incl. number of
vdevs, target fw is able to handle), but here we missed this split.

Ben has a valid point, the TARGET_10X_NUM_VDEVS claims to be 16, so
there's an inconsistency between what we adverts to mac in max
interfaces, but I'm not sure if this is such a big deal.

It would be good to clear have that in the commit log so that anyone can
understand what bug is fixed.

Do you want me to send a v2 with just an updated commit (better user
impact description)? (No patch content changes)

-Bartosz