[PATCH 1/3] riscv: Do not return error if reserved node already exists

[Bin Meng]

Hi Atish,

On Wed, Jun 24, 2020 at 2:17 AM Atish Patra <atishp at atishpatra.org> wrote:
>
> On Tue, Jun 23, 2020 at 12:24 AM Bin Meng <bmeng.cn at gmail.com> wrote:
> >
> > Hi Atish,
> >
> > On Fri, Jun 19, 2020 at 9:52 AM Atish Patra <atish.patra at wdc.com> wrote:
> > >
> > > Not all errors are fatal. If a reserved memory node already exists in the
> > > destination device tree, we can continue to boot without failing.
> > >
> > > Signed-off-by: Atish Patra <atish.patra at wdc.com>
> > > ---
> > >  arch/riscv/lib/fdt_fixup.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/riscv/lib/fdt_fixup.c b/arch/riscv/lib/fdt_fixup.c
> > > index 6db48ad04a56..91524d9a5ae9 100644
> > > --- a/arch/riscv/lib/fdt_fixup.c
> > > +++ b/arch/riscv/lib/fdt_fixup.c
> > > @@ -62,7 +62,7 @@ int riscv_fdt_copy_resv_mem_node(const void *src, void *dst)
> > >                 pmp_mem.end = addr + size - 1;
> > >                 err = fdtdec_add_reserved_memory(dst, basename, &pmp_mem,
> > >                                                  &phandle);
> > > -               if (err < 0) {
> > > +               if (err < 0 && err != FDT_ERR_EXISTS) {
> >
> > This FDT_ERR_EXISTS error code is possibly returned by:
> >
> >     node = fdt_add_subnode(blob, parent, name);
> >     if (node < 0)
> >         return node;
> >
> > But if it exists, I believe fdtdec_add_reserved_memory() already
> > returns 0 because they are likely to have the same range of memory
> > block start address and size, no?
> >
>
> Currently, yes. As libfdt and fdtdec_add_reserved_memory external to
> this code, functionality
> can change without modifying fdt_fixup.c knowingly or unknowingly.
> FDT_ERR_EXISTS is harmless error in this context and we shouldn't
> cause boot failure because of that.
> That's why I add that exclusion.

Okay. But the error should be checked against -FDT_ERR_EXISTS.

Regards,
Bin