[PATCH 6/6] net: octeontx: smi: fix mii probe

[Tim Harvey]

On Mon, Apr 26, 2021 at 10:19 PM Stefan Roese <sr at denx.de> wrote:
>
> Hi Tim,
>
> On 26.03.21 16:55, Tim Harvey wrote:
> > On Thu, Mar 25, 2021 at 11:48 PM Stefan Roese <sr at denx.de> wrote:
> >>
> >> On 26.03.21 01:07, Tim Harvey wrote:
> >>> The fdt node offset is apparently not set properly when probed
> >>> causing no MDIO busses to be found. Fix this by obtaining the
> >>> offset.
> >>>
> >>> Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> >>
> >> Reviewed-by: Stefan Roese <sr at denx.de>
> >>
> >> Thanks,
> >> Stefan
> >>
> >>> ---
> >>>    drivers/net/octeontx/smi.c | 2 ++
> >>>    1 file changed, 2 insertions(+)
> >>>
> >>> diff --git a/drivers/net/octeontx/smi.c b/drivers/net/octeontx/smi.c
> >>> index 91dcd05e4b..27f4423c6a 100644
> >>> --- a/drivers/net/octeontx/smi.c
> >>> +++ b/drivers/net/octeontx/smi.c
> >>> @@ -325,6 +325,8 @@ int octeontx_smi_probe(struct udevice *dev)
> >>>                return -1;
> >>>        }
> >>>
> >>> +     node = fdt_node_offset_by_compatible(gd->fdt_blob, -1,
> >>> +                                          "cavium,thunder-8890-mdio-nexus");
> >>>        fdt_for_each_subnode(subnode, gd->fdt_blob, node) {
> >>>                ret = fdt_node_check_compatible(gd->fdt_blob, subnode,
> >>>                                                "cavium,thunder-8890-mdio");
> >>>
> >
> > Honestly this is the wrong fix for this issue and I'm hoping someone
> > could educate me. I'm a bit confused at why there are several ways to
> > work with dt (int offsets vs ofnodes which are unions of int offsets
> > and node pointers???).
> >
> > The above patch was not needed previously so something changed in the
> > ofnode field of struct udevice between v2019.10 and v2021.01.
> >
> > Simon, could you explain what the proper way to work with dev->ofnode
> > in probe functions is to loop over subnodes?
>
> This version is in mainline now. Tim, could you please re-visit this
> and perhaps switch to using live tree API, as suggested by Suneel:
>
>         ofnode_for_each_subnode(subnode, dev_ofnode(dev)) {
>                 ret = ofnode_device_is_compatible(subnode,
>                         "cavium,thunder-8890-mdio");
>

Stefan,

Yes, I can submit this but I would really like to understand the
original issue. Do you or Simon perhaps know why the fdt node offset
in dev passed to probe is wrong? It's not null but it does not appear
to point to a device-tree (or perhaps I was using the wrong functions
on it not fully understanding the current state of this live tree
API).

Best regards,

Tim