Re: [PATCH 1/2] i2c: synquacer: Fix an error handling path in synquacer_i2c_probe()

From: Ard Biesheuvel
Date: Fri Jan 12 2024 - 12:50:36 EST


On Sat, 6 Jan 2024 at 13:48, Christophe JAILLET
<christophe.jaillet@xxxxxxxxxx> wrote:
>
> If an error occurs after the clk_prepare_enable() call, it should be undone
> by a corresponding clk_disable_unprepare() call, as already done in the
> remove() function.
>
> As devm_clk_get() is used, we can switch to devm_clk_get_enabled() to
> handle it automatically and fix the probe.
>
> Update the remove() function accordingly and remove the now useless
> clk_disable_unprepare() call.
>
> Fixes: 0d676a6c4390 ("i2c: add support for Socionext SynQuacer I2C controller")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>

> ---
> drivers/i2c/busses/i2c-synquacer.c | 20 +++++++-------------
> 1 file changed, 7 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-synquacer.c b/drivers/i2c/busses/i2c-synquacer.c
> index bbea521b05dd..a73f5bb9a164 100644
> --- a/drivers/i2c/busses/i2c-synquacer.c
> +++ b/drivers/i2c/busses/i2c-synquacer.c
> @@ -550,17 +550,13 @@ static int synquacer_i2c_probe(struct platform_device *pdev)
> device_property_read_u32(&pdev->dev, "socionext,pclk-rate",
> &i2c->pclkrate);
>
> - i2c->pclk = devm_clk_get(&pdev->dev, "pclk");
> - if (PTR_ERR(i2c->pclk) == -EPROBE_DEFER)
> - return -EPROBE_DEFER;
> - if (!IS_ERR_OR_NULL(i2c->pclk)) {
> - dev_dbg(&pdev->dev, "clock source %p\n", i2c->pclk);
> -
> - ret = clk_prepare_enable(i2c->pclk);
> - if (ret)
> - return dev_err_probe(&pdev->dev, ret, "failed to enable clock\n");
> - i2c->pclkrate = clk_get_rate(i2c->pclk);
> - }
> + i2c->pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
> + if (IS_ERR(i2c->pclk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(i2c->pclk),
> + "failed to get and enable clock\n");
> +
> + dev_dbg(&pdev->dev, "clock source %p\n", i2c->pclk);
> + i2c->pclkrate = clk_get_rate(i2c->pclk);
>
> if (i2c->pclkrate < SYNQUACER_I2C_MIN_CLK_RATE ||
> i2c->pclkrate > SYNQUACER_I2C_MAX_CLK_RATE)
> @@ -615,8 +611,6 @@ static void synquacer_i2c_remove(struct platform_device *pdev)
> struct synquacer_i2c *i2c = platform_get_drvdata(pdev);
>
> i2c_del_adapter(&i2c->adapter);
> - if (!IS_ERR(i2c->pclk))
> - clk_disable_unprepare(i2c->pclk);
> };
>
> static const struct of_device_id synquacer_i2c_dt_ids[] __maybe_unused = {
> --
> 2.34.1
>