[U-Boot] [PATCH] [v2] powerpc/85xx: fix compatible property for the L2 cache node

[Scott Wood]

On Fri, 29 Apr 2011 22:30:58 +0200
Wolfgang Denk <wd at denx.de> wrote:

> Dear Timur Tabi,
> 
> In message <1304089126-11945-1-git-send-email-timur at freescale.com> you wrote:
> > The compatible property for the L2 cache node (on 85xx systems that don't
> > have a CPC) was using a value for the property length that did not match
> > the actual length of the property.
> > 
> > Signed-off-by: Timur Tabi <timur at freescale.com>
> > ---
> >  arch/powerpc/cpu/mpc85xx/fdt.c |   13 +++++++------
> >  1 files changed, 7 insertions(+), 6 deletions(-)
> > 
> > diff --git a/arch/powerpc/cpu/mpc85xx/fdt.c b/arch/powerpc/cpu/mpc85xx/fdt.c
> > index 642f6c5..a3a4b65 100644
> > --- a/arch/powerpc/cpu/mpc85xx/fdt.c
> > +++ b/arch/powerpc/cpu/mpc85xx/fdt.c
> > @@ -165,7 +165,6 @@ static inline void ft_fixup_l2cache(void *blob)
> >  	int len, off;
> >  	u32 *ph;
> >  	struct cpu_type *cpu = identify_cpu(SVR_SOC_VER(get_svr()));
> > -	char compat_buf[38];
> >  
> >  	const u32 line_size = 32;
> >  	const u32 num_ways = 8;
> > @@ -192,22 +191,24 @@ static inline void ft_fixup_l2cache(void *blob)
> >  	}
> >  
> >  	if (cpu) {
> > +		char compat_buf[40];
> > +
> >  		if (isdigit(cpu->name[0]))
> >  			len = sprintf(compat_buf,
> > -				"fsl,mpc%s-l2-cache-controller", cpu->name);
> > +				"fsl,mpc%s-l2-cache-controller" "%c" "cache",
> > +				cpu->name, 0);
> 
> This is a somewhat funny and complicated way of writing
> 
> 				"fsl,mpc%s-l2-cache-controller\0cache"

Except that his version works and your version doesn't.  With your version
sprintf will stop reading the format string after "controller".

> which, when written in plain text, reveals what sort of trickery you
> are doing here.
> 
> This code is a dirty hack, and I will not accept it.

The alternative is two separate sprintfs, manually advancing the pointer in
the calling code, but that's a bit more complicated and error-prone (the
previous code did it that way, and had an error, thus this patch) and IMHO
not more readable.

-Scott