Re: [PATCH 1/3] regulator: wm8994: Revert back to using devres

From: Marek Szyprowski
Date: Fri Nov 23 2018 - 04:24:37 EST


Hi Charles,

On 2018-11-22 18:30, Charles Keepax wrote:
> This reverts commit 466affa06703 ("regulator: wm8994: Don't
> use devres for enable GPIOs"). Whilst that did work around the
> issue in question there are complications on the error paths of
> regulator_register. In the success case clearly the regulator
> core owns the GPIO, however, in the failure case it is unclear
> what should happen. The regulator core could always free the
> GPIO but that may not make sense from the perspective of the
> calling code. Alternatively the regulator core could never free
> the GPIO but that makes the handling in the regulator core rather
> complex. Ultimately it makes more sense to handle the shared GPIO
> in the core.
>
> Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>

Thanks for sorting this out! Works fine on Trats2:

Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

> ---
> drivers/regulator/wm8994-regulator.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/regulator/wm8994-regulator.c b/drivers/regulator/wm8994-regulator.c
> index 46e6b4ee1491a..d7fec533c4032 100644
> --- a/drivers/regulator/wm8994-regulator.c
> +++ b/drivers/regulator/wm8994-regulator.c
> @@ -147,14 +147,11 @@ static int wm8994_ldo_probe(struct platform_device *pdev)
> config.regmap = wm8994->regmap;
> config.init_data = &ldo->init_data;
>
> - /*
> - * Look up LDO enable GPIO from the parent device node, we don't
> - * use devm because the regulator core will free the GPIO
> - */
> - gpiod = gpiod_get_optional(pdev->dev.parent,
> - id ? "wlf,ldo2ena" : "wlf,ldo1ena",
> - GPIOD_OUT_LOW |
> - GPIOD_FLAGS_BIT_NONEXCLUSIVE);
> + /* Look up LDO enable GPIO from the parent device node */
> + gpiod = devm_gpiod_get_optional(pdev->dev.parent,
> + id ? "wlf,ldo2ena" : "wlf,ldo1ena",
> + GPIOD_OUT_LOW |
> + GPIOD_FLAGS_BIT_NONEXCLUSIVE);
> if (IS_ERR(gpiod))
> return PTR_ERR(gpiod);
> config.ena_gpiod = gpiod;
> @@ -187,7 +184,6 @@ static int wm8994_ldo_probe(struct platform_device *pdev)
> return 0;
>
> err:
> - gpiod_put(gpiod);
> return ret;
> }
>

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland