Re: Re: [PATCH net-next v2 6/9] net: phy: add backplane kr driver support

[Andrew Lunn]

On Fri, Apr 24, 2020 at 02:39:54PM +0000, Florinel Iordache wrote:
> > > +/* Backplane custom logging */
> > > +#define bpdev_fn(fn)                                                 \
> > > +void bpdev_##fn(struct phy_device *phydev, char *fmt, ...)           \
> > > +{                                                                    \
> > > +     struct va_format vaf = {                                        \
> > > +             .fmt = fmt,                                             \
> > > +     };                                                              \
> > > +     va_list args;                                                   \
> > > +     va_start(args, fmt);                                            \
> > > +     vaf.va = &args;                                                 \
> > > +     if (!phydev->attached_dev)                                      \
> > > +             dev_##fn(&phydev->mdio.dev, "%pV", &vaf);               \
> > > +     else                                                            \
> > > +             dev_##fn(&phydev->mdio.dev, "%s: %pV",                  \
> > > +                     netdev_name(phydev->attached_dev), &vaf);       \
> > > +     va_end(args);                                                   \
> > > +}
> > > +
> > > +bpdev_fn(err)
> > > +EXPORT_SYMBOL(bpdev_err);
> > > +
> > > +bpdev_fn(warn)
> > > +EXPORT_SYMBOL(bpdev_warn);
> > > +
> > > +bpdev_fn(info)
> > > +EXPORT_SYMBOL(bpdev_info);
> > > +
> > > +bpdev_fn(dbg)
> > > +EXPORT_SYMBOL(bpdev_dbg);
> > 
> > Didn't i say something about just using phydev_{err|warn|info|dbg}?
> > 
> >        Andrew
> 
> Hi Andrew,
> 
> I used this custom logging in order to be able to add any kind of useful information we might need to all prints (err/warn/info/dbg).
> For example all these bpdev_ functions are equivalent with phydev_ but only in the case when there is no attached device: phydev->attached_dev == NULL.
> Otherwise, if there is a device attached, then we also want to add its name to all these prints in order to know to which device the information refers to.
> For example in this case the print looks like this:
> [   50.853515] backplane_qoriq 8c13000:00: eth1: 10gbase-kr link trained, Tx equalization: C(-1)=0x0, C(0)=0x29, C(+1)=0x5
> This is very useful because we can see very easy to which interface the information printed is related to: in this case the link was trained for interface: eth1
> This information (the name of attached device: eth1) is not printed by phydev_ functions.
> I'm sorry I have not explained all this earlier, the first time when you asked about it. 

So why not argue that the phydev_* functions should be extended to
include this information? Is this extra information only valuable for
link training, or for anything a PHY does? If the core does not do
something, fix the core, rather than work around it in your driver.

     Andrew