Re: [Intel-wired-lan] [PATCH iwl-next v3] igb: Retrieve Tx timestamp directly from interrupt for i210

[Sebastian Andrzej Siewior]

On 2026-02-11 13:44:36 [-0800], Jakub Kicinski wrote:
> On Wed, 11 Feb 2026 11:29:03 -0800 Jacob Keller wrote:
> > > Moving the timestamping in IRQ looked like a good solution, because the
> > > device already signals that the Tx timestamp is available now. No need
> > > to schedule any worker/work at all. So, it'd be very nice if
> > > skb_tstamp_tx() could be called from IRQ context. BTW other drivers like
> > > igc call this function in IRQ context as well.
> > 
> > Right. Reporting the timestamp from the interrupt is the simplest and 
> > lowest latency method. I know Miroslav had some situations and devices 
> > where it apparently caused more problems than it helped, though I don't 
> > believe anyone else has reproduced those?
> 
> There's a BH workqueue now, as a replacement for tasklets.
> Presumably smallest fix would be to switch to that?

Hmm. This would raise the TASKLET softirq from the interrupt handler and
then handle it on the irq-exit path. 
Let me look if that one lock can be removed first…

Sebastian