linux-kernel - Re: [PATCH v1 1/4] i2c: mpc: Use devm_clk_get

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Date:   Tue, 13 Apr 2021 23:34:43 +0000
From:   Chris Packham <Chris.Packham@...iedtelesis.co.nz>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        "linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     "wsa@...nel.org" <wsa@...nel.org>
Subject: Re: [PATCH v1 1/4] i2c: mpc: Use devm_clk_get_optional()


On 14/04/21 2:37 am, Andy Shevchenko wrote:
> The peripheral clock is optional and we may get an -EPROBE_DEFER error code
> which would not be propagated correctly, fix this by using
> devm_clk_get_optional().
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

Reviewed-by: Chris Packham <chris.packham@...iedtelesis.co.nz>

None of the systems I have access to make use of the clocks property so 
I can't do much testing. I can say it still handles the absence of a 
clocks property correctly.

> ---
>   drivers/i2c/busses/i2c-mpc.c | 25 ++++++++++++-------------
>   1 file changed, 12 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
> index 3c8bcdfff7e7..6dc029a31d36 100644
> --- a/drivers/i2c/busses/i2c-mpc.c
> +++ b/drivers/i2c/busses/i2c-mpc.c
> @@ -690,17 +690,18 @@ static int fsl_i2c_probe(struct platform_device *op)
>   	 * enable clock for the I2C peripheral (non fatal),
>   	 * keep a reference upon successful allocation
>   	 */
> -	clk = devm_clk_get(&op->dev, NULL);
> -	if (!IS_ERR(clk)) {
> -		err = clk_prepare_enable(clk);
> -		if (err) {
> -			dev_err(&op->dev, "failed to enable clock\n");
> -			return err;
> -		} else {
> -			i2c->clk_per = clk;
> -		}
> +	clk = devm_clk_get_optional(&op->dev, NULL);
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
> +	err = clk_prepare_enable(clk);
> +	if (err) {
> +		dev_err(&op->dev, "failed to enable clock\n");
> +		return err;
>   	}
>   
> +	i2c->clk_per = clk;
> +
>   	if (of_property_read_bool(op->dev.of_node, "fsl,preserve-clocking")) {
>   		clock = MPC_I2C_CLOCK_PRESERVE;
>   	} else {
> @@ -744,8 +745,7 @@ static int fsl_i2c_probe(struct platform_device *op)
>   	return 0;
>   
>    fail_add:
> -	if (i2c->clk_per)
> -		clk_disable_unprepare(i2c->clk_per);
> +	clk_disable_unprepare(i2c->clk_per);
>   
>   	return result;
>   };
> @@ -756,8 +756,7 @@ static int fsl_i2c_remove(struct platform_device *op)
>   
>   	i2c_del_adapter(&i2c->adap);
>   
> -	if (i2c->clk_per)
> -		clk_disable_unprepare(i2c->clk_per);
> +	clk_disable_unprepare(i2c->clk_per);
>   
>   	return 0;
>   };