[PATCH u-boot-marvell v2 8/9] arm: mvebu: spl: Use IS_ENABLED() instead of #ifdef where possible

[Marek Behún]

On Tue, 14 Dec 2021 10:36:00 +0100
Pali Rohár <pali at kernel.org> wrote:

> On Friday 26 November 2021 15:37:37 Marek Behún wrote:
> > @@ -340,17 +333,17 @@ void board_init_f(ulong dummy)
> >  	timer_init();
> >  
> >  	/* Armada 375 does not support SerDes and DDR3 init yet */
> > -#if !defined(CONFIG_ARMADA_375)
> > -	/* First init the serdes PHY's */
> > -	serdes_phy_config();
> > -
> > -	/* Setup DDR */
> > -	ret = ddr3_init();
> > -	if (ret) {
> > -		debug("ddr3_init() failed: %d\n", ret);
> > -		hang();
> > +	if (!IS_ENABLED(CONFIG_ARMADA_375)) {
> > +		/* First init the serdes PHY's */
> > +		serdes_phy_config();
> > +
> > +		/* Setup DDR */
> > +		ret = ddr3_init();
> > +		if (ret) {
> > +			debug("ddr3_init() failed: %d\n", ret);
> > +			hang();
> > +		}
> >  	}
> > -#endif  
> 
> As written in comment above there is no SerDes and DDR3 support for
> Armada 375 and therefore there is no serdes_phy_config() or ddr3_init()
> function. So this code needs not to be compiled at all and usage of
> #ifdef is correct here.

#ifdefs are almost never correct in C-files, for the parts of the code
they guard isn't put through syntactic analysis, and can therefore
contain bugs which we are not warned about.

Using if (IS_ENABLED()) almost never producess a different binary,
because the code is optimized away.

Marek