Re: Spurious timeouts in mvmdio

[Leigh Brown]

On 2013-12-03 22:45, Sebastian Hesselbarth wrote:
> On 12/03/2013 09:57 PM, Leigh Brown wrote:
[...]
> > Nicolas' patch should fix the issue, but I prefer the following as it 
> > is
> > more
> > correct, as it only adjusts the timeout when calling
> > wait_event_timeout().  As
> > I said above,I believe the polling code is correct.
> >
> > diff --git a/drivers/net/ethernet/marvell/mvmdio.c
> > b/drivers/net/ethernet/marvell/mvmdio.c
> > index 7354960..b187c08 100644
> > --- a/drivers/net/ethernet/marvell/mvmdio.c
> > +++ b/drivers/net/ethernet/marvell/mvmdio.c
> > @@ -92,6 +92,14 @@ static int orion_mdio_wait_ready(struct mii_bus 
> > *bus)
> >               if (time_is_before_jiffies(end))
> >                   ++timedout;
> >               } else {
> > +            /*
> > +             * wait_event_timeout does not guarantee a delay of at
> > +             * least one whole jiffie, so timeout must be no less
> > +             * than two.
> > +             */
> > +            if (timeout < 2)
> > +                timeout = 2;
>
> If you always want to wait at least two jiffies, why not just increase
> TIMEOUT makro to 20ms instead of messing here with it again?
> As said on IRC log above, originally timeout was 100ms.
>
> Sebastian

You could do that, but would you not feel bad leaving a latent bug in 
the code?
I know it's unlikely that someone would set HZ to 50, but if they did, 
the same
bug would appear again.

Regards,

Leigh.



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/