Re: [PATCH net-next v12 01/15] phylink: Add phylink_mac_interrupt

[Andrew Lunn <andrew@lunn.ch>]

On Sun, Sep 27, 2026 at 11:03:17AM +0200, Birger Koblitz wrote:
> 
> 
> On 17/09/2026 11:24 pm, netdev-bot+sashiko@kernel.org wrote:
> > Thank you for your contribution! Sashiko AI review found 2 potential
> > issue(s) to consider:
> > 
> > Critical: 0 · High: 0 · Medium: 1 · Low: 1
> > 
> > - [Medium] `phylink_mac_interrupt()`
> >    (drivers/net/phy/phylink.c:1621-1628) reads `pl->phydev` with no…
> 
> This does not look like an actual problem, as the interrupt is not really an
> IRQ, it is a call from the MAC layer, calling phy_mac_interrupt(phy) did the
> same in the past.

We need to be a little bit careful here. phy_mac_interrupt(phy) can be
called in interrupt context. It does not perform any blocking
operations, it just queues up the work to handle the actual event.

Here it is used in interrupt context.
https://elixir.bootlin.com/linux/v7.2.8/source/drivers/net/ethernet/broadcom/asp2/bcmasp.c#L81

I would expect the phylink equivalent to be the same.

Since we are in interrupt context we cannot take a mutex. But do we
need to worry about phydev disappearing? I don't think so. In
practice, ignoring unbind via sysfs, the only way for a PHY to
disappear is for an SFP module to be hot unplugged. But SPF don't
support interrupts, so there should be no need to use
phylink_mac_interrupt().

It might be worth adding some comments here?

   Andrew