Re: [PATCH] iio: adc: ad7192: Avoid disabling a clock that was never enabled.

[Alexandru Ardelean <ardeleanalex@gmail.com>]

On Sun, May 9, 2021 at 2:42 PM Jonathan Cameron <jic23@kernel.org> wrote:
>
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
> Found by inspection.
>
> If the internal clock source is being used, the driver doesn't
> call clk_prepare_enable() and as such we should not call
> clk_disable_unprepare()
>
> Use the same condition to protect the disable path as is used
> on the enable one.  Note this will all get simplified when
> the driver moves over to a full devm_ flow, but that would make
> backporting the fix harder.
>
> Fix obviously predates move out of staging, but backporting will
> become more complex (and is unlikely to happen), hence that patch
> is given in the fixes tag.
>

This also looks like a conversion to devm_ would help.
But later.

Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>

> Fixes: b581f748cce0 ("staging: iio: adc: ad7192: move out of staging")
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Alexandru Tachici <alexandru.tachici@analog.com>
> Cc: Alexandru Ardelean <ardeleanalex@gmail.com>
> ---
>  drivers/iio/adc/ad7192.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
> index 2ed580521d81..d3be67aa0522 100644
> --- a/drivers/iio/adc/ad7192.c
> +++ b/drivers/iio/adc/ad7192.c
> @@ -1014,7 +1014,9 @@ static int ad7192_probe(struct spi_device *spi)
>         return 0;
>
>  error_disable_clk:
> -       clk_disable_unprepare(st->mclk);
> +       if (st->clock_sel == AD7192_CLK_EXT_MCLK1_2 ||
> +           st->clock_sel == AD7192_CLK_EXT_MCLK2)
> +               clk_disable_unprepare(st->mclk);
>  error_remove_trigger:
>         ad_sd_cleanup_buffer_and_trigger(indio_dev);
>  error_disable_dvdd:
> @@ -1031,7 +1033,9 @@ static int ad7192_remove(struct spi_device *spi)
>         struct ad7192_state *st = iio_priv(indio_dev);
>
>         iio_device_unregister(indio_dev);
> -       clk_disable_unprepare(st->mclk);
> +       if (st->clock_sel == AD7192_CLK_EXT_MCLK1_2 ||
> +           st->clock_sel == AD7192_CLK_EXT_MCLK2)
> +               clk_disable_unprepare(st->mclk);
>         ad_sd_cleanup_buffer_and_trigger(indio_dev);
>
>         regulator_disable(st->dvdd);
> --
> 2.31.1
>