[U-Boot] [PATCH v2 1/2] libfdt: Correct fdt handling of overlays without fixups and base trees without symbols

[Simon Glass]

On 21 December 2016 at 03:58, Stefan Agner <stefan at agner.ch> wrote:
> From: David Gibson <david at gibson.dropbear.id.au>
>
> The fdt_overlay_apply() function purports to support the edge cases where
> an overlay has no fixups to be applied, or a base tree which has no
> symbols (the latter can only work if the former is also true).  However it
> gets it wrong in a couple of small ways:
>
>   * In the no fixups case, it doesn't fail immediately, but will attempt
>     fdt_for_each_property_offset() giving -FDT_ERR_NOTFOUND as the node
>     offset, which will fail.  Instead it should succeed immediately, since
>     there's nothing to do.
>   * In the case of no symbols, it again doesn't fail immediately.  However
>     if there is an actual fixup it will fail with an unexpected error,
>     because -FDT_ERR_NOTFOUND is passed to fdt_getprop() when attempting to
>     look up the symbols.  We should instead return -FDT_ERR_NOTFOUND
>     directly.
>
> Both of these errors lead to the code returning misleading error codes in
> failing cases.
>
> [ DTC commit: 7d8ef6e1db9794f72805a0855f4f7f12fadd03d3 ]
>
> Signed-off-by: David Gibson <david at gibson.dropbear.id.au>
> Signed-off-by: Stefan Agner <stefan.agner at toradex.com>
> ---
>
> Changes in v2:
> - Backported patch from libfdt
>
>  lib/libfdt/fdt_overlay.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

Acked-by: Simon Glass <sjg at chromium.org>