Re: [PATCH v1 0/3] Clean up and fix error handling in mdio_mux_init()

[Kevin Hilman]

On Thu, Aug 5, 2021 at 11:36 AM Kevin Hilman <khilman@xxxxxxxxxxxx> wrote:
>
> Marc Zyngier <maz@xxxxxxxxxx> writes:
>
> > Hi Saravana,
> >
> > On Wed, 04 Aug 2021 22:43:29 +0100,
> > Saravana Kannan <saravanak@xxxxxxxxxx> wrote:
> >>
> >> This patch series was started due to -EPROBE_DEFER not being handled
> >> correctly in mdio_mux_init() and causing issues [1]. While at it, I also
> >> did some more error handling fixes and clean ups. The -EPROBE_DEFER fix is
> >> the last patch.
> >>
> >> Ideally, in the last patch we'd treat any error similar to -EPROBE_DEFER
> >> but I'm not sure if it'll break any board/platforms where some child
> >> mdiobus never successfully registers. If we treated all errors similar to
> >> -EPROBE_DEFER, then none of the child mdiobus will work and that might be a
> >> regression. If people are sure this is not a real case, then I can fix up
> >> the last patch to always fail the entire mdio-mux init if any of the child
> >> mdiobus registration fails.
> >>
> >> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> >> Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> >> Cc: Kevin Hilman <khilman@xxxxxxxxxxxx>
> >> [1] - https://lore.kernel.org/lkml/CAGETcx95kHrv8wA-O+-JtfH7H9biJEGJtijuPVN0V5dUKUAB3A@xxxxxxxxxxxxxx/#t
> >>
> >> Saravana Kannan (3):
> >>   net: mdio-mux: Delete unnecessary devm_kfree
> >>   net: mdio-mux: Don't ignore memory allocation errors
> >>   net: mdio-mux: Handle -EPROBE_DEFER correctly
> >>
> >>  drivers/net/mdio/mdio-mux.c | 37 ++++++++++++++++++++++++-------------
> >>  1 file changed, 24 insertions(+), 13 deletions(-)
> >
> > Thanks for this. I've just gave it a go on my test platform, and this
> > indeed addresses the issues I was seeing [1].
> >
> > Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
> > Tested-by: Marc Zyngier <maz@xxxxxxxxxx>
>
> I wasn't seeing the same issues as Marc, but am heavily using everything
> as modules on a few platforms using this code, and I'm not seeing any
> regressions.
>
> Thanks Saravana for finding the root cause here.
>
> Acked-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
> Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxx>

Oops, that should not be a SoB, but rather:

Tested-by: Kevin Hilman <khilman@xxxxxxxxxxxx>