linux-kernel - Re: [PATCH v2 19/20] media: i2c: ov4689: Refactor ov4689_s

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Message-ID: <20240223114849.GU31348@pendragon.ideasonboard.com>
Date: Fri, 23 Feb 2024 13:48:49 +0200
From: Laurent Pinchart <laurent.pinchart@...asonboard.com>
To: Mikhail Rudenko <mike.rudenko@...il.com>
Cc: linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
	Sakari Ailus <sakari.ailus@...ux.intel.com>,
	Jacopo Mondi <jacopo@...ndi.org>,
	Tommaso Merciai <tomm.merciai@...il.com>,
	Christophe JAILLET <christophe.jaillet@...adoo.fr>,
	Dave Stevenson <dave.stevenson@...pberrypi.com>,
	Mauro Carvalho Chehab <mchehab@...nel.org>
Subject: Re: [PATCH v2 19/20] media: i2c: ov4689: Refactor ov4689_s_stream

Hi Mikhail,

Thank you for the patch.

On Mon, Dec 18, 2023 at 08:40:40PM +0300, Mikhail Rudenko wrote:
> Remove repetitive pm_runtime_put calls in ov4689_s_stream function,
> and call pm_runtime_put once at the end of the "on" branch if any
> error occurred.
> 
> Signed-off-by: Mikhail Rudenko <mike.rudenko@...il.com>
> ---
>  drivers/media/i2c/ov4689.c | 29 ++++++++++-------------------
>  1 file changed, 10 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov4689.c b/drivers/media/i2c/ov4689.c
> index e997c3231e85..884761d02119 100644
> --- a/drivers/media/i2c/ov4689.c
> +++ b/drivers/media/i2c/ov4689.c
> @@ -555,35 +555,26 @@ static int ov4689_s_stream(struct v4l2_subdev *sd, int on)
>  					  ov4689_common_regs,
>  					  ARRAY_SIZE(ov4689_common_regs),
>  					  NULL);
> -		if (ret) {
> -			pm_runtime_put_sync(dev);
> -			goto unlock_and_return;
> -		}
> +		if (ret)
> +			goto cleanup_pm;
>  
>  		ret = ov4689_setup_timings(ov4689, sd_state);
> -		if (ret) {
> -			pm_runtime_put(dev);
> -			goto unlock_and_return;
> -		}
> +		if (ret)
> +			goto cleanup_pm;
>  
>  		ret = ov4689_setup_blc_anchors(ov4689, sd_state);
> -		if (ret) {
> -			pm_runtime_put(dev);
> -			goto unlock_and_return;
> -		}
> +		if (ret)
> +			goto cleanup_pm;
>  
>  		ret = __v4l2_ctrl_handler_setup(&ov4689->ctrl_handler);
> -		if (ret) {
> -			pm_runtime_put_sync(dev);
> -			goto unlock_and_return;
> -		}
> +		if (ret)
> +			goto cleanup_pm;
>  
>  		ret = cci_write(ov4689->regmap, OV4689_REG_CTRL_MODE,
>  				OV4689_MODE_STREAMING, NULL);
> -		if (ret) {
> +cleanup_pm:

A label within an if branch isn't great, readability-wise :-S Could we
maybe split the ov4687_s_stream() function in two (streamon and
streamoff, or similar names) ? You would then have a single
pm_runtime_put_sync() call in ov4689_s_stream(), in the error handling
path for the streamon function call.

> +		if (ret)
>  			pm_runtime_put_sync(dev);
> -			goto unlock_and_return;
> -		}
>  	} else {
>  		cci_write(ov4689->regmap, OV4689_REG_CTRL_MODE,
>  			  OV4689_MODE_SW_STANDBY, NULL);

-- 
Regards,

Laurent Pinchart