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;
Date:   Fri, 8 Apr 2022 12:07:21 +0200
From:   Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
To:     Wan Jiabing <wanjiabing@vivo.com>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Lee Jones <lee.jones@linaro.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        linux-pwm@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pwm: sifive: simplify if-if to if-else
Message-ID: <20220408100721.rinvvgard3nr5wff@pengutronix.de>
References: <20220408083007.41538-1-wanjiabing@vivo.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="5hmg2yezfbimyu7f"
Content-Disposition: inline
In-Reply-To: <20220408083007.41538-1-wanjiabing@vivo.com>
Precedence: bulk


--5hmg2yezfbimyu7f
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Fri, Apr 08, 2022 at 04:30:07PM +0800, Wan Jiabing wrote:
> use if and else instead of if(A) and if (!A).
>=20
> Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
> ---
>  drivers/pwm/pwm-sifive.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>=20
> diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c
> index 253c4a17d255..e6d05a329002 100644
> --- a/drivers/pwm/pwm-sifive.c
> +++ b/drivers/pwm/pwm-sifive.c
> @@ -138,10 +138,9 @@ static int pwm_sifive_enable(struct pwm_chip *chip, =
bool enable)
>  			dev_err(ddata->chip.dev, "Enable clk failed\n");
>  			return ret;
>  		}
> -	}
> -
> -	if (!enable)
> +	} else {
>  		clk_disable(ddata->clk);
> +	}
> =20
>  	return 0;
>  }

The patch looks fine. I wonder if it would be sensible to clean up even
more: pwm_sifive_apply() is only a single caller of
pwm_sifive_enable(). If this is optimized to skip the duty_cycle and
period calculation for the state->enabled =3D false case and just disables
the clock this should still work.

Also I wonder if there is a clk mismatch issue in this driver: .probe
enables the clk and if the PWM is off (i.e. .get_state diagnoses that)
the clock will never be disabled while the driver is bound, will it?

Best regards
Uwe

--=20
Pengutronix e.K.                           | Uwe Kleine-K=F6nig            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

--5hmg2yezfbimyu7f
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iQEzBAABCgAdFiEEfnIqFpAYrP8+dKQLwfwUeK3K7AkFAmJQCVcACgkQwfwUeK3K
7Al38Af7BAOq90kL/kjCqKlWjXccUKG6Dj3BDwGcg5UfGg/JRiJmYayalIAR2LIn
mKa9mxv/NmCLa9jl5uPCJ5WqvJnmYcdz4rL11wXGwlEY93YYn56FOG0U7MBo1ij9
NUdVK8np9+RnN2HYy3YWeiIwGnHFu4xoU9Iv1ahdfPGw+UAPiH2VSYCUkQguXjZ5
0Lf49mFIHiOBjyiWCHO2pV1k7JWAXLlbPbSthFLufhdQORrYkfqb6K+o8/LfgPtL
VswPzS7Hd/LNUzP3pHKF1tig1XNRMaTq1E+vkG4x680WLeVgCzWxeIjqeB+wZFar
8g21tTWYs3nI8bfyBzbE27vAwKI58w==
=xpSm
-----END PGP SIGNATURE-----

--5hmg2yezfbimyu7f--