linux-kernel - Re: [PATCH 3/9] clk: meson: axg-audio: Don't reference clk_init

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Date:   Tue, 06 Aug 2019 14:48:52 -0700
From:   Stephen Boyd <sboyd@...nel.org>
To:     Jerome Brunet <jbrunet@...libre.com>,
        Michael Turquette <mturquette@...libre.com>
Cc:     linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
        Neil Armstrong <narmstrong@...libre.com>
Subject: Re: [PATCH 3/9] clk: meson: axg-audio: Don't reference clk_init_data after registration

Quoting Jerome Brunet (2019-08-06 01:49:47)
> On Wed 31 Jul 2019 at 12:35, Stephen Boyd <sboyd@...nel.org> wrote:
> 
> > A future patch is going to change semantics of clk_register() so that
> > clk_hw::init is guaranteed to be NULL after a clk is registered. Avoid
> > referencing this member here so that we don't run into NULL pointer
> > exceptions.
> 
> Hi Stephen,
> 
> What to do you indend to do with this one ? Will you apply directly or
> should we take it ?

I said below:

 Please ack so I can take this through clk tree

> 
> We have several changes for the controller which may conflict with this
> one. It is nothing major but the sooner I know how this changes goes in,
> the sooner I can rebase the rest.

Will it conflict? I can deal with conflicts.

> 
> Also, We were (re)using the init_data only on register failures.
> I understand that you want to guarantee .init is NULL when the clock is
> registered, but it this particular case, the registeration failed so the
> clock is not registered.
> 
> IMO, it would be better if devm_clk_hw_register() left the init_data
> untouched if the registration fails.

Do you have other usage of the init_data besides printing out the name?
I think we could have devm_clk_hw_register() print out the name of the
clk that failed to register instead, and get rid of more code in drivers
that way. Unless of course there are other uses of the init struct?

> 
> >
> > Cc: Neil Armstrong <narmstrong@...libre.com>
> > Cc: Jerome Brunet <jbrunet@...libre.com>
> > Signed-off-by: Stephen Boyd <sboyd@...nel.org>
> > ---
> >
> > Please ack so I can take this through clk tree
> >
> >  drivers/clk/meson/axg-audio.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >