On Fri, 2016-07-01 at 04:50 +0000, Yuval Mintz wrote:

quoted

currently all the device driver call  netif_tx_start_all_queues(dev)
on open to W/A this issue. which is strange since only
real_num_tx_queues are active.

You could also argue that netif_tx_start_all_queues() should
only enable the real_num_tx_queues.
[Although that would obviously cause all drivers to reach the
'problem' you're currently fixing].

Yep. Basically what I pointed out.

It seems inconsistent to have loops using num_tx_queues, and others
using real_num_tx_queues.

Instead of 'fixing' one of them, we should take a deeper look, even if
the change looks fine.

num_tx_queues should be used in code that runs once, like
netdev_lockdep_set_classes(), but other loops should probably use
real_num_tx_queues.

Anyway all these changes should definitely target net-next, not net
tree.