[PATCH] regulator: fp9931: Fix error handling for optional regulator

[PATCH] regulator: fp9931: Fix error handling for optional regulator

[Robby Cai]

If "vin" reg does not exist in the device tree, the regulator framework
returns -ENODEV, which is normal for an optional supply. But the current
code treats -ENODEV as a fatal error, causing the driver probe to fail.
This patch fixes that by handling -ENODEV correctly for optional regulator.

Fixes: 12d821bd13d4 ("regulator: Add FP9931/JD9930 driver")
Signed-off-by: Robby Cai <robby.cai@nxp.com>
---
 drivers/regulator/fp9931.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/regulator/fp9931.c b/drivers/regulator/fp9931.c
index 7fbcc6327cc63..fa7f32adfb666 100644
--- a/drivers/regulator/fp9931.c
+++ b/drivers/regulator/fp9931.c
@@ -448,9 +448,13 @@ static int fp9931_probe(struct i2c_client *client)
 				     "failed to allocate regmap!\n");
 
 	data->vin_reg = devm_regulator_get_optional(&client->dev, "vin");
-	if (IS_ERR(data->vin_reg))
-		return dev_err_probe(&client->dev, PTR_ERR(data->vin_reg),
-				     "failed to get vin regulator\n");
+	if (IS_ERR(data->vin_reg)) {
+		if (PTR_ERR(data->vin_reg) != -ENODEV)
+			return dev_err_probe(&client->dev, PTR_ERR(data->vin_reg),
+					     "failed to get vin regulator\n");
+
+		data->vin_reg = NULL;
+	}
 
 	data->pgood_gpio = devm_gpiod_get(&client->dev, "pg", GPIOD_IN);
 	if (IS_ERR(data->pgood_gpio))
-- 
2.37.1

Re: [PATCH] regulator: fp9931: Fix error handling for optional regulator

[Mark Brown]

On Thu, 12 Mar 2026 12:01:48 +0800, Robby Cai wrote:
> If "vin" reg does not exist in the device tree, the regulator framework
> returns -ENODEV, which is normal for an optional supply. But the current
> code treats -ENODEV as a fatal error, causing the driver probe to fail.
> This patch fixes that by handling -ENODEV correctly for optional regulator.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/1] regulator: fp9931: Fix error handling for optional regulator
      commit: 8066a5855ed986f822df4d8b1fa8017b88a43e76

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Re: [PATCH] regulator: fp9931: Fix error handling for optional regulator

[Andreas Kemnade]

On Thu, 12 Mar 2026 12:01:48 +0800
Robby Cai <robby.cai@nxp.com> wrote:

> If "vin" reg does not exist in the device tree, the regulator framework
> returns -ENODEV, which is normal for an optional supply. But the current
> code treats -ENODEV as a fatal error, causing the driver probe to fail.
> This patch fixes that by handling -ENODEV correctly for optional regulator.
> 
> Fixes: 12d821bd13d4 ("regulator: Add FP9931/JD9930 driver")
> Signed-off-by: Robby Cai <robby.cai@nxp.com>
> ---
>  drivers/regulator/fp9931.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/regulator/fp9931.c b/drivers/regulator/fp9931.c
> index 7fbcc6327cc63..fa7f32adfb666 100644
> --- a/drivers/regulator/fp9931.c
> +++ b/drivers/regulator/fp9931.c
> @@ -448,9 +448,13 @@ static int fp9931_probe(struct i2c_client *client)
>  				     "failed to allocate regmap!\n");
>  
>  	data->vin_reg = devm_regulator_get_optional(&client->dev, "vin");

looking at that thing again. I think I have abused the optional api.
Of course this chip needs a supply. It may be hardwired so something
not switchable. But that needs to be wired to something... So I think
rather the _optional is wrong here.

Regards,
Andreas

Re: [PATCH] regulator: fp9931: Fix error handling for optional regulator

[Mark Brown]

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On Thu, Mar 12, 2026 at 06:58:54PM +0100, Andreas Kemnade wrote:
> Robby Cai <robby.cai@nxp.com> wrote:

> >  	data->vin_reg = devm_regulator_get_optional(&client->dev, "vin");

> looking at that thing again. I think I have abused the optional api.
> Of course this chip needs a supply. It may be hardwired so something
> not switchable. But that needs to be wired to something... So I think
> rather the _optional is wrong here.

If it's a mandatory supply that's right, I may have misunderstood what
the supply was doing when I originally reviewed this.

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Re: [PATCH] regulator: fp9931: Fix error handling for optional regulator

[Robby Cai]

On Thu, Mar 12, 2026 at 06:00:54PM +0000, Mark Brown wrote:
> On Thu, Mar 12, 2026 at 06:58:54PM +0100, Andreas Kemnade wrote:
> > Robby Cai <robby.cai@nxp.com> wrote:
> 
> > >  	data->vin_reg = devm_regulator_get_optional(&client->dev, "vin");
> 
> > looking at that thing again. I think I have abused the optional api.
> > Of course this chip needs a supply. It may be hardwired so something
> > not switchable. But that needs to be wired to something... So I think
> > rather the _optional is wrong here.
> 
> If it's a mandatory supply that's right, I may have misunderstood what
> the supply was doing when I originally reviewed this.

Thanks for the review. This does make sense. I'll send out patch v2 soon.

Regards,
Robby

Re: [PATCH] regulator: fp9931: Fix error handling for optional regulator

[Robby Cai]

On Thu, Mar 12, 2026 at 06:58:54PM +0100, Andreas Kemnade wrote:
> On Thu, 12 Mar 2026 12:01:48 +0800
> Robby Cai <robby.cai@nxp.com> wrote:
> 
> > If "vin" reg does not exist in the device tree, the regulator framework
> > returns -ENODEV, which is normal for an optional supply. But the current
> > code treats -ENODEV as a fatal error, causing the driver probe to fail.
> > This patch fixes that by handling -ENODEV correctly for optional regulator.
> > 
> > Fixes: 12d821bd13d4 ("regulator: Add FP9931/JD9930 driver")
> > Signed-off-by: Robby Cai <robby.cai@nxp.com>
> > ---
> >  drivers/regulator/fp9931.c | 10 +++++++---
> >  1 file changed, 7 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/regulator/fp9931.c b/drivers/regulator/fp9931.c
> > index 7fbcc6327cc63..fa7f32adfb666 100644
> > --- a/drivers/regulator/fp9931.c
> > +++ b/drivers/regulator/fp9931.c
> > @@ -448,9 +448,13 @@ static int fp9931_probe(struct i2c_client *client)
> >  				     "failed to allocate regmap!\n");
> >  
> >  	data->vin_reg = devm_regulator_get_optional(&client->dev, "vin");
> 
> looking at that thing again. I think I have abused the optional api.
> Of course this chip needs a supply. It may be hardwired so something
> not switchable. But that needs to be wired to something... So I think
> rather the _optional is wrong here.
> 
> Regards,
> Andreas

Thanks for the review. That's right. I'll send out new patch for review.

Regards,
Robby