Re: [PATCH] FDDI: defxx: simplify if-if to if-else

From: Andrew Lunn
Date: Mon Apr 25 2022 - 08:07:05 EST


On Mon, Apr 25, 2022 at 12:26:10AM +0100, Maciej W. Rozycki wrote:
> On Mon, 25 Apr 2022, Andrew Lunn wrote:
>
> > > NAK. The first conditional optionally sets `bp->mmio = false', which
> > > changes the value of `dfx_use_mmio' in some configurations:
> > >
> > > #if defined(CONFIG_EISA) || defined(CONFIG_PCI)
> > > #define dfx_use_mmio bp->mmio
> > > #else
> > > #define dfx_use_mmio true
> > > #endif
> >
> > Which is just asking for trouble like this.
> >
> > Could i suggest dfx_use_mmio is changed to DFX_USE_MMIO to give a hint
> > something horrible is going on.
>
> There's legacy behind it, `dfx_use_mmio' used to be a proper variable and
> references were retained not to obfuscate the changes that ultimately led
> to the current arrangement. I guess at this stage it could be changed to
> a function-like macro or a static inline function taking `bp' as the
> argument.

Yes, something like that would be good.

> > It probably won't stop the robots finding this if (x) if (!x), but
> > there is a chance the robot drivers will wonder why it is upper case.
>
> Well, blindly relying on automation is bound to cause trouble.

Unfortunately, there are a number of bot drivers who do blindly rely
on automation. We have had to undo the same broken bot driven changes
a few times, and ended up adding extra comments to catch the eye of
the bot drivers.

Andrew