On Wed, 4 Sep 2024 14:36:58 +0200 Andrew Lunn <and...@lunn.ch> wrote:
> On Wed, Sep 04, 2024 at 10:27:11AM +0200, Maxime Chevallier wrote: > > Hi Andrew, > > > > On Fri, 30 Aug 2024 23:06:08 +0200 > > Andrew Lunn <and...@lunn.ch> wrote: > > > > > > --- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c > > > > +++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c > > > > @@ -649,12 +649,7 @@ static void fs_adjust_link(struct net_device *dev) > > > > unsigned long flags; > > > > > > > > spin_lock_irqsave(&fep->lock, flags); > > > > - > > > > - if (fep->ops->adjust_link) > > > > - fep->ops->adjust_link(dev); > > > > - else > > > > - generic_adjust_link(dev); > > > > - > > > > + generic_adjust_link(dev); > > > > spin_unlock_irqrestore(&fep->lock, flags); > > > > > > Holding a spinlock is pretty unusual. We are in thread context, and > > > the phydev mutex is held. Looking at generic_adjust_link, do any of > > > the fep->foo variables actually need protecting, particularly from > > > changes in interrupts context? > > > > Yes there are, the interrupt mask/event registers are being accessed > > from the interrupt handler and the ->restart() hook. I can try to > > rework this a bit for a cleaner interrupt handling, but I don't have > > means to test this on all mac flavors (fec/fcc/scc) :( > > As far as i can see, none of the fep->old* members are accessed > outside of fs_enet-main.c. There values are not important for the > restart call. So the spinlock has nothing to do with adjust_link as > such, but restart. So maybe narrow down the lock to just the restart > call? But it is not a big issues, just unusual. I agree with you on that, and this is actually what end-up happening in the final phylink conversion patch (only the restart() call gets called wthin the spinlock). I'll however include a patch that does exactly what you suggest as part of the phylink conversion, both to make the big port-to-phylink patch smaller, but also to better document why we only need to care about the restart() part, if that's ok :) Thanks, Maxime
