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From: "Uwe Kleine-König" <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
Date: Fri, 8 Apr 2022 12:07:21 +0200	[thread overview]
Message-ID: <20220408100721.rinvvgard3nr5wff@pengutronix.de> (raw)
In-Reply-To: <20220408083007.41538-1-wanjiabing@vivo.com>


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On Fri, Apr 08, 2022 at 04:30:07PM +0800, Wan Jiabing wrote:
> use if and else instead of if(A) and if (!A).
> 
> Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
> ---
>  drivers/pwm/pwm-sifive.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> 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);
> +	}
>  
>  	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 = 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

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

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  reply	other threads:[~2022-04-08 10:08 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-08  8:30 [PATCH] pwm: sifive: simplify if-if to if-else Wan Jiabing
2022-04-08 10:07 ` Uwe Kleine-König [this message]
2022-05-20 13:59 ` Thierry Reding

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