Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <0c19d8dedda3e308c75a6c97358d2af3.sboyd@kernel.org>
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
In-Reply-To: <185a3f0a326.b623e6bd1243489.6765528573167668508@linux.beauty>
References: <20230110114540.2975540-1-me@linux.beauty> <57d1f58c4c6cca793d629d5776b477d0.sboyd@kernel.org> <185a3f0a326.b623e6bd1243489.6765528573167668508@linux.beauty>
Subject: Re: [PATCH] clk: create write_enable file to control clk rate write and other dangerous ops permission
From:   Stephen Boyd <sboyd@kernel.org>
Cc:     michael turquette <mturquette@baylibre.com>,
        li chen <lchen@ambarella.com>,
        linux-clk <linux-clk@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
To:     Li Chen <me@linux.beauty>
Date:   Thu, 12 Jan 2023 11:18:11 -0800
User-Agent: alot/0.10
Precedence: bulk

Quoting Li Chen (2023-01-11 19:05:34)
> Hi Stephen,
>  ---- On Thu, 12 Jan 2023 02:37:29 +0800  Stephen Boyd  wrote ---=20
>  > Quoting Li Chen (2023-01-10 03:45:39)
>  > > From: Li Chen lchen@ambarella.com>
>  > >=20
>  > > It's common requirement for bsp debug/test to change clk rate from u=
serspace.
>  > >=20
>  > > Currently, we must define CLKOCK_ALLOW_WRITE_DEBUGFS then re-compile=
 kernel
>  > > to allow this feature. Let's replace it with a "write_enable" file to
>  > > allow enable it at runtime.
>  >=20
>  > Nak. This design is intentional.
> =20
> Thanks for your reply. Got it. But sometimes re-compile is somewhat low e=
fficient. Is it acceptable to provide=20
> a write_enable to clk_core(not enable by default), and allow clk driver t=
o enable it inside clk_ops->init
> via clk_hw->core->write_enable =3D 1?
>=20

No