On Wed, Nov 16, 2016 at 10:49:06AM -0800, Eric Dumazet wrote:
On Wed, Nov 16, 2016 at 10:01 AM, Brian Starkey <brian.star...@arm.com> wrote:
The smc91x driver does seem to have some trickiness around softirqs.
I'm not familiar with net drivers, but I'll see if I can figure
anything out there.
Oh this code looks ugly :(
Do you have CONFIG_SMP=y or not ?
Yeah CONFIG_SMP=y (and CONFIG_PREEMPT=y too, fwiw).
I did try forcing it into the no-op locking (as though config SMP
wasn't set), it didn't help (and it doesn't look like that would be
safe with CONFIG_PREEMPT=y either).
The bit in smc_hardware_send_pkt looks like skipping softirq
invocation when there's already one running wouldn't give the same
behaviour as before:
if (!smc_special_trylock(&lp->lock, flags)) {
netif_stop_queue(dev);
tasklet_schedule(&lp->tx_task);
return;
}
... that said, I've no idea if that matters.
Of course I also don't know if the network driver is even to blame :-(
Cheers,
-Brian
