[U-Boot] [PATCH v2] fdt_support: Use VLA instead of MEMORY_BANKS_MAX

[Ramon Fried]

On Sun, Aug 12, 2018 at 11:02 PM Lukasz Majewski <lukma at denx.de> wrote:
>
> Hi Ramon,
>
> > Instead of relaying on user to configure MEMORY_BANKS_MAX
> > correctly, use VLA (variable length array) to accommodate the
> > required banks.
> >
> > Fixes: 2a1f4f1758b5 ("Revert "fdt_support: Use CONFIG_NR_DRAM_BANKS if
> > defined"")
> >
> > Signed-off-by: Ramon Fried <ramon.fried at gmail.com>
> > ---
> > Resending same patch but with the right email address
> >  common/fdt_support.c | 9 ++-------
> >  1 file changed, 2 insertions(+), 7 deletions(-)
> >
> > diff --git a/common/fdt_support.c b/common/fdt_support.c
> > index 34d2bd59c4..e8982367a0 100644
> > --- a/common/fdt_support.c
> > +++ b/common/fdt_support.c
> > @@ -409,19 +409,14 @@ static int fdt_pack_reg(const void *fdt, void
> > *buf, u64 *address, u64 *size, return p - (char *)buf;
> >  }
> >
> > -#define MEMORY_BANKS_MAX 4
> >  int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int
> > banks) {
> >       int err, nodeoffset;
> >       int len, i;
> > -     u8 tmp[MEMORY_BANKS_MAX * 16]; /* Up to 64-bit address +
> > 64-bit size */
> > +     u8 tmp[banks * 16]; /* Up to 64-bit address + 64-bit size */
>
> Why cannot we read the RAM size from "memory" DTS property?
> SDRAM is continuous - there are no "holes" in it.
>
> The memory banks and their sizes are going to be replaced by DTS
> "memory" description anyway.
>
I'm not sure I understand what your suggesting.
The whole purpose of this function is to fixup the DTS, so how can we
read the information from it ?

> >
> > -     if (banks > MEMORY_BANKS_MAX) {
> > -             printf("%s: num banks %d exceeds hardcoded limit %d."
> > -                    " Recompile with higher MEMORY_BANKS_MAX?\n",
> > -                    __FUNCTION__, banks, MEMORY_BANKS_MAX);
> > +     if (!banks)
> >               return -1;
> > -     }
> >
> >       err = fdt_check_header(blob);
> >       if (err < 0) {
>
>
>
>
> Best regards,
>
> Lukasz Majewski
>
> --
>
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
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