[PATCH 00/18] mfd: Convert to platform remove callback returning void

[PATCH 00/18] mfd: Convert to platform remove callback returning void

[Uwe Kleine-König]

Hello,

this series converts all platform drivers below drivers/mfd to use
.remove_new(). Compared to the traditional .remove() callback
.remove_new() returns no value. This is a good thing because the driver
core doesn't (and cannot) cope for errors during remove. The only effect
of a non-zero return value in .remove() is that the driver core emits a
warning. The device is removed anyhow and an early return from .remove()
usually yields resource leaks and/or use-after-free bugs.

See commit 5c5a7680e67b ("platform: Provide a remove callback that
returns no value") for an extended explanation and the eventual goal.

All drivers converted here already returned zero unconditionally in
.remove(), so they are converted here trivially.

Best regards
Uwe

Uwe Kleine-König (18):
  mfd: ab8500-sysctrl: Convert to platform remove callback returning
    void
  mfd: cros_ec_dev: Convert to platform remove callback returning void
  mfd: exynos-lpass: Convert to platform remove callback returning void
  mfd: fsl-imx25-tsadc: Convert to platform remove callback returning
    void
  mfd: hi655x-pmic: Convert to platform remove callback returning void
  mfd: intel-lpss-acpi: Convert to platform remove callback returning
    void
  mfd: kempld-core: Convert to platform remove callback returning void
  mfd: mcp-sa11x0: Convert to platform remove callback returning void
  mfd: mxs-lradc: Convert to platform remove callback returning void
  mfd: omap-usb-host: Convert to platform remove callback returning void
  mfd: omap-usb-tll: Convert to platform remove callback returning void
  mfd: pcf50633-adc: Convert to platform remove callback returning void
  mfd: qcom-pm8xxx: Convert to platform remove callback returning void
  mfd: sm501: Convert to platform remove callback returning void
  mfd: stm32-timers: Convert to platform remove callback returning void
  mfd: ti_am335x_tscadc: Convert to platform remove callback returning
    void
  mfd: tps65911-comparator: Convert to platform remove callback
    returning void
  mfd: twl4030-audio: Convert to platform remove callback returning void

 drivers/mfd/ab8500-sysctrl.c      | 6 ++----
 drivers/mfd/cros_ec_dev.c         | 5 ++---
 drivers/mfd/exynos-lpass.c        | 6 ++----
 drivers/mfd/fsl-imx25-tsadc.c     | 6 ++----
 drivers/mfd/hi655x-pmic.c         | 5 ++---
 drivers/mfd/intel-lpss-acpi.c     | 6 ++----
 drivers/mfd/kempld-core.c         | 6 ++----
 drivers/mfd/mcp-sa11x0.c          | 6 ++----
 drivers/mfd/mxs-lradc.c           | 6 ++----
 drivers/mfd/omap-usb-host.c       | 5 ++---
 drivers/mfd/omap-usb-tll.c        | 5 ++---
 drivers/mfd/pcf50633-adc.c        | 6 ++----
 drivers/mfd/qcom-pm8xxx.c         | 6 ++----
 drivers/mfd/sm501.c               | 6 ++----
 drivers/mfd/stm32-timers.c        | 6 ++----
 drivers/mfd/ti_am335x_tscadc.c    | 6 ++----
 drivers/mfd/tps65911-comparator.c | 6 ++----
 drivers/mfd/twl4030-audio.c       | 6 ++----
 18 files changed, 36 insertions(+), 68 deletions(-)

base-commit: 3ff7a5781ceee3befb9224d29cef6e6a4766c5fe
-- 
2.42.0

[PATCH 13/18] mfd: qcom-pm8xxx: Convert to platform remove callback returning void

[Uwe Kleine-König]

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/mfd/qcom-pm8xxx.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/qcom-pm8xxx.c b/drivers/mfd/qcom-pm8xxx.c
index 07c531bd1236..8b6285f687da 100644
--- a/drivers/mfd/qcom-pm8xxx.c
+++ b/drivers/mfd/qcom-pm8xxx.c
@@ -585,19 +585,17 @@ static int pm8xxx_remove_child(struct device *dev, void *unused)
 	return 0;
 }
 
-static int pm8xxx_remove(struct platform_device *pdev)
+static void pm8xxx_remove(struct platform_device *pdev)
 {
 	struct pm_irq_chip *chip = platform_get_drvdata(pdev);
 
 	device_for_each_child(&pdev->dev, NULL, pm8xxx_remove_child);
 	irq_domain_remove(chip->irqdomain);
-
-	return 0;
 }
 
 static struct platform_driver pm8xxx_driver = {
 	.probe		= pm8xxx_probe,
-	.remove		= pm8xxx_remove,
+	.remove_new	= pm8xxx_remove,
 	.driver		= {
 		.name	= "pm8xxx-core",
 		.of_match_table = pm8xxx_id_table,
-- 
2.42.0

Re: [PATCH 13/18] mfd: qcom-pm8xxx: Convert to platform remove callback returning void

[Konrad Dybcio]

On 11/6/23 18:17, Uwe Kleine-König wrote:
> The .remove() callback for a platform driver returns an int which makes
> many driver authors wrongly assume it's possible to do error handling by
> returning an error code. However the value returned is ignored (apart
> from emitting a warning) and this typically results in resource leaks.
> 
> To improve here there is a quest to make the remove callback return
> void. In the first step of this quest all drivers are converted to
> .remove_new(), which already returns void. Eventually after all drivers
> are converted, .remove_new() will be renamed to .remove().
> 
> Trivially convert this driver from always returning zero in the remove
> callback to the void returning variant.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad

Re: [PATCH 00/18] mfd: Convert to platform remove callback returning void

[Lee Jones]

On Mon, 06 Nov 2023 18:17:09 +0100, Uwe Kleine-König wrote:
> this series converts all platform drivers below drivers/mfd to use
> .remove_new(). Compared to the traditional .remove() callback
> .remove_new() returns no value. This is a good thing because the driver
> core doesn't (and cannot) cope for errors during remove. The only effect
> of a non-zero return value in .remove() is that the driver core emits a
> warning. The device is removed anyhow and an early return from .remove()
> usually yields resource leaks and/or use-after-free bugs.
> 
> [...]

Applied, thanks!

[01/18] mfd: ab8500-sysctrl: Convert to platform remove callback returning void
        commit: 35cf346f9fa92ceb19c5d2edc4409a7d384da8ee
[02/18] mfd: cros_ec_dev: Convert to platform remove callback returning void
        commit: 981c92a1d65a7ccce2d814c66ff2deecca304672
[03/18] mfd: exynos-lpass: Convert to platform remove callback returning void
        commit: 2d859aa8e081884c0c02d738925cba23a8cfb1b8
[04/18] mfd: fsl-imx25-tsadc: Convert to platform remove callback returning void
        commit: f215b75acc85254a29404b32c871b7ff2ea8da2a
[09/18] mfd: mxs-lradc: Convert to platform remove callback returning void
        commit: beb1f9e6382f59339e118594c94ee6b5ac96f3ec
[10/18] mfd: omap-usb-host: Convert to platform remove callback returning void
        commit: 231927898ae91049aa35d237c556cc216d80e8f7
[11/18] mfd: omap-usb-tll: Convert to platform remove callback returning void
        commit: 83d4e355240147db7597ea1ce64624fcdaaee6ae
[13/18] mfd: qcom-pm8xxx: Convert to platform remove callback returning void
        commit: ae3bcd5b09e35f363aa1744d38f90fda2b40e9ca
[15/18] mfd: stm32-timers: Convert to platform remove callback returning void
        commit: aeebc47f8d479c363e24fba0201ef8dca417fe6e
[18/18] mfd: twl4030-audio: Convert to platform remove callback returning void
        commit: 3716978b584a8baaba16d64c93eb0fed0edcbc3b

--
Lee Jones [李琼斯]

Re: [PATCH 00/18] mfd: Convert to platform remove callback returning void

[Lee Jones]

On Mon, 06 Nov 2023, Uwe Kleine-König wrote:

> Hello,
> 
> this series converts all platform drivers below drivers/mfd to use
> .remove_new(). Compared to the traditional .remove() callback
> .remove_new() returns no value. This is a good thing because the driver
> core doesn't (and cannot) cope for errors during remove. The only effect
> of a non-zero return value in .remove() is that the driver core emits a
> warning. The device is removed anyhow and an early return from .remove()
> usually yields resource leaks and/or use-after-free bugs.
> 
> See commit 5c5a7680e67b ("platform: Provide a remove callback that
> returns no value") for an extended explanation and the eventual goal.
> 
> All drivers converted here already returned zero unconditionally in
> .remove(), so they are converted here trivially.
> 
> Best regards
> Uwe
> 
> Uwe Kleine-König (18):
>   mfd: ab8500-sysctrl: Convert to platform remove callback returning
>     void
>   mfd: cros_ec_dev: Convert to platform remove callback returning void
>   mfd: exynos-lpass: Convert to platform remove callback returning void
>   mfd: fsl-imx25-tsadc: Convert to platform remove callback returning
>     void
>   mfd: hi655x-pmic: Convert to platform remove callback returning void
>   mfd: intel-lpss-acpi: Convert to platform remove callback returning
>     void
>   mfd: kempld-core: Convert to platform remove callback returning void
>   mfd: mcp-sa11x0: Convert to platform remove callback returning void
>   mfd: mxs-lradc: Convert to platform remove callback returning void
>   mfd: omap-usb-host: Convert to platform remove callback returning void
>   mfd: omap-usb-tll: Convert to platform remove callback returning void
>   mfd: pcf50633-adc: Convert to platform remove callback returning void
>   mfd: qcom-pm8xxx: Convert to platform remove callback returning void
>   mfd: sm501: Convert to platform remove callback returning void
>   mfd: stm32-timers: Convert to platform remove callback returning void
>   mfd: ti_am335x_tscadc: Convert to platform remove callback returning
>     void
>   mfd: tps65911-comparator: Convert to platform remove callback
>     returning void
>   mfd: twl4030-audio: Convert to platform remove callback returning void

Looks like you missed the mailing list on a bunch of these.

I'm going to remove this set for now.

Could you please resubmit it and Cc: LKML?

>  drivers/mfd/ab8500-sysctrl.c      | 6 ++----
>  drivers/mfd/cros_ec_dev.c         | 5 ++---
>  drivers/mfd/exynos-lpass.c        | 6 ++----
>  drivers/mfd/fsl-imx25-tsadc.c     | 6 ++----
>  drivers/mfd/hi655x-pmic.c         | 5 ++---
>  drivers/mfd/intel-lpss-acpi.c     | 6 ++----
>  drivers/mfd/kempld-core.c         | 6 ++----
>  drivers/mfd/mcp-sa11x0.c          | 6 ++----
>  drivers/mfd/mxs-lradc.c           | 6 ++----
>  drivers/mfd/omap-usb-host.c       | 5 ++---
>  drivers/mfd/omap-usb-tll.c        | 5 ++---
>  drivers/mfd/pcf50633-adc.c        | 6 ++----
>  drivers/mfd/qcom-pm8xxx.c         | 6 ++----
>  drivers/mfd/sm501.c               | 6 ++----
>  drivers/mfd/stm32-timers.c        | 6 ++----
>  drivers/mfd/ti_am335x_tscadc.c    | 6 ++----
>  drivers/mfd/tps65911-comparator.c | 6 ++----
>  drivers/mfd/twl4030-audio.c       | 6 ++----
>  18 files changed, 36 insertions(+), 68 deletions(-)
> 
> base-commit: 3ff7a5781ceee3befb9224d29cef6e6a4766c5fe
> -- 
> 2.42.0
> 

-- 
Lee Jones [李琼斯]