Hi Geert-san,
> From: Geert Uytterhoeven, Sent: Friday, October 13, 2023 6:19 PM
>
> Hi Shimoda-san,
>
> On Fri, Oct 13, 2023 at 10:55 AM Yoshihiro Shimoda
> <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > > From: Geert Uytterhoeven, Sent: Friday, October 13, 2023 4:29 PM
> > > On Fri, Oct 13, 2023 at 4:10 AM Yoshihiro Shimoda
> > > <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > > > > From: Geert Uytterhoeven, Sent: Thursday, October 12, 2023 9:35 PM
> > > > > On Thu, Oct 12, 2023 at 2:16 PM Yoshihiro Shimoda
> > > > > <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > > > > > Add PM ops for Suspend to Idle. When the system suspended,
> > > > > > the Ethernet Serdes's clock will be stopped. So, this driver needs
> > > > > > to re-initialize the Ethernet Serdes by phy_init() in
> > > > > > renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().
> > > > > >
> > > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>
> > > > > > --- a/drivers/net/ethernet/renesas/rswitch.c
> > > > > > +++ b/drivers/net/ethernet/renesas/rswitch.c
> > > > > > @@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
> > > > > > platform_set_drvdata(pdev, NULL);
> > > > > > }
> > > > > >
> > > > > > +static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
> > > > > > +{
> > > > > > + struct rswitch_private *priv = dev_get_drvdata(dev);
> > > > > > + struct net_device *ndev;
> > > > > > + int i;
> > > > >
> > > > > unsigned int (also below)
> > > >
> > > > I don't know why unsigned int is needed. Other functions use
> > >
> > > There's this old mantra "prefer unsigned over signed in C",
> > > and a valid port array index here is always unsigned.
> >
> > I understood it.
> >
> > > > rswitch_for_each_enabled_port{_continue_reverse}() with int.
> > > > Especially, rswitch_for_each_enabled_port_continue_reverse()
> > > > has the following code, unsigned int will not work correctly:
> > >
> > > Oh, there is also a reverse variant, which indeed needs a signed
> > > iterator, currently...
> > >
> > > > ---
> > > > #define rswitch_for_each_enabled_port_continue_reverse(priv, i) \
> > > > for (i--; i >= 0; i--) \
> > >
> > > I think this can be made to work with an unsigned iterator using
> > >
> > > for (; i-- > 0; )
> >
> > I think that this loop cannot access index 0 :)
>
> rswitch_for_each_enabled_port_continue_reverse() is meant to be
> used in the error path, to tear down all ports that were initialized
> succesfully? So i is always the index of the first port that failed to
> initialize, i.e. i > 0 on entry.
>
> See "git grep -Ww rswitch_for_each_enabled_port_continue_reverse".
Thank you for your comment. And I'm sorry, I completely misunderstood
about "for (; i-- > 0; )" behavior... I should have tested this before
I send such a comment...
Best regards,
Yoshihiro Shimoda
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
