linux-kernel - Re: [PATCH 3/6] clk: mediatek: reset: Return reset data pointer on register

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Date:   Fri, 20 May 2022 10:42:40 +0200
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>
To:     Yassine Oudjana <yassine.oudjana@...il.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Philipp Zabel <p.zabel@...gutronix.de>
Cc:     Yassine Oudjana <y.oudjana@...tonmail.com>,
        Chen-Yu Tsai <wenst@...omium.org>,
        Miles Chen <miles.chen@...iatek.com>,
        Chun-Jie Chen <chun-jie.chen@...iatek.com>,
        José Expósito <jose.exposito89@...il.com>,
        Rex-BC Chen <rex-bc.chen@...iatek.com>,
        linux-mediatek@...ts.infradead.org, linux-clk@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        ~postmarketos/upstreaming@...ts.sr.ht
Subject: Re: [PATCH 3/6] clk: mediatek: reset: Return reset data pointer on
 register

Il 19/05/22 15:47, Yassine Oudjana ha scritto:
> From: Yassine Oudjana <y.oudjana@...tonmail.com>
> 
> Return a struct mtk_clk_rst_data * when registering a reset
> controller in preparation for adding an unregister helper
> that will take it as an argument. Make the necessary changes
> in drivers that do not currently discard the return value
> of register functions.
> 
> Signed-off-by: Yassine Oudjana <y.oudjana@...tonmail.com>

Hello Yassine,

Thanks for your efforts on helping to make the MediaTek clocks better - I agree
(and I'm not the only one..) that there's a lot of work to do on this side.

Though... I don't think that this is the right direction: you're right about
properly unregistering (in patch 4/6) the reset controllers on rmmod/failure
but I'm not sure that this kind of noise brings any benefit.

Explaining:
You definitely saw that there's a new register _with_dev, which uses devm ops
and that's going to automatically cleanup in case of removal/failure.
This is what we should do.

Hence, my proposal is to drop patch 3/6, 4/6, 5/6 and (slowly, steadily) migrate
all of the MediaTek clocks from CLK_OF_DECLARE() to platform drivers (which also
means that we can eventually change them to tristate!), so that we slowly remove
all users of all functions that are not "_with_dev", and that we finally remove
all of these then-unused functions as well.

Making sure that I don't get misunderstood:
      I'm not implying that this huge migration work is on your shoulders!

P.S.: Chen-Yu, Miles: do you also agree? :-)

Cheers,
Angelo