[PATCH 00/30] pwm: Convert to platform remove callback returning void

[PATCH 00/30] pwm: Convert to platform remove callback returning void

[Uwe Kleine-König]

Hello,

this patch series adapts the platform drivers below drivers/pwm to use
the .remove_new() callback. 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 a resource leak.

By changing the remove callback to return void driver authors cannot
reasonably assume any more that there is some kind of cleanup later.

All drivers touched here returned zero unconditionally in their remove
callback, so they could all be converted trivially to .remove_new().

Note that this series depends on commit 5c5a7680e67b ("platform: Provide
a remove callback that returns no value") that is already in Linus' tree
but not yet included in a tagged version.

Best regards
Uwe

Uwe Kleine-König (30):
  pwm: atmel-hlcdc: Convert to platform remove callback returning void
  pwm: atmel-tcb: Convert to platform remove callback returning void
  pwm: atmel: Convert to platform remove callback returning void
  pwm: bcm-iproc: Convert to platform remove callback returning void
  pwm: bcm2835: Convert to platform remove callback returning void
  pwm: berlin: Convert to platform remove callback returning void
  pwm: brcmstb: Convert to platform remove callback returning void
  pwm: clk: Convert to platform remove callback returning void
  pwm: cros-ec: Convert to platform remove callback returning void
  pwm: hibvt: Convert to platform remove callback returning void
  pwm: img: Convert to platform remove callback returning void
  pwm: imx-tpm: Convert to platform remove callback returning void
  pwm: lpc18xx-sct: Convert to platform remove callback returning void
  pwm: lpss-platform: Convert to platform remove callback returning void
  pwm: mtk-disp: Convert to platform remove callback returning void
  pwm: omap-dmtimer: Convert to platform remove callback returning void
  pwm: rcar: Convert to platform remove callback returning void
  pwm: rockchip: Convert to platform remove callback returning void
  pwm: samsung: Convert to platform remove callback returning void
  pwm: sifive: Convert to platform remove callback returning void
  pwm: spear: Convert to platform remove callback returning void
  pwm: sprd: Convert to platform remove callback returning void
  pwm: sti: Convert to platform remove callback returning void
  pwm: stm32: Convert to platform remove callback returning void
  pwm: sun4i: Convert to platform remove callback returning void
  pwm: tegra: Convert to platform remove callback returning void
  pwm: tiecap: Convert to platform remove callback returning void
  pwm: tiehrpwm: Convert to platform remove callback returning void
  pwm: vt8500: Convert to platform remove callback returning void
  pwm: xilinx: Convert to platform remove callback returning void

 drivers/pwm/pwm-atmel-hlcdc.c   | 6 ++----
 drivers/pwm/pwm-atmel-tcb.c     | 6 ++----
 drivers/pwm/pwm-atmel.c         | 6 ++----
 drivers/pwm/pwm-bcm-iproc.c     | 6 ++----
 drivers/pwm/pwm-bcm2835.c       | 6 ++----
 drivers/pwm/pwm-berlin.c        | 6 ++----
 drivers/pwm/pwm-brcmstb.c       | 6 ++----
 drivers/pwm/pwm-clk.c           | 6 ++----
 drivers/pwm/pwm-cros-ec.c       | 6 ++----
 drivers/pwm/pwm-hibvt.c         | 6 ++----
 drivers/pwm/pwm-img.c           | 6 ++----
 drivers/pwm/pwm-imx-tpm.c       | 6 ++----
 drivers/pwm/pwm-lpc18xx-sct.c   | 6 ++----
 drivers/pwm/pwm-lpss-platform.c | 5 ++---
 drivers/pwm/pwm-mtk-disp.c      | 6 ++----
 drivers/pwm/pwm-omap-dmtimer.c  | 6 ++----
 drivers/pwm/pwm-rcar.c          | 6 ++----
 drivers/pwm/pwm-rockchip.c      | 6 ++----
 drivers/pwm/pwm-samsung.c       | 6 ++----
 drivers/pwm/pwm-sifive.c        | 6 ++----
 drivers/pwm/pwm-spear.c         | 6 ++----
 drivers/pwm/pwm-sprd.c          | 6 ++----
 drivers/pwm/pwm-sti.c           | 6 ++----
 drivers/pwm/pwm-stm32.c         | 6 ++----
 drivers/pwm/pwm-sun4i.c         | 6 ++----
 drivers/pwm/pwm-tegra.c         | 6 ++----
 drivers/pwm/pwm-tiecap.c        | 6 ++----
 drivers/pwm/pwm-tiehrpwm.c      | 6 ++----
 drivers/pwm/pwm-vt8500.c        | 6 ++----
 drivers/pwm/pwm-xilinx.c        | 5 ++---
 30 files changed, 60 insertions(+), 118 deletions(-)

base-commit: 2eb29d59ddf02e39774abfb60b2030b0b7e27c1f
-- 
2.39.1

[PATCH 09/30] pwm: cros-ec: 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 (mostly) ignored
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.

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/pwm/pwm-cros-ec.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 86df6702cb83..90afce212fb0 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -328,14 +328,12 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int cros_ec_pwm_remove(struct platform_device *dev)
+static void cros_ec_pwm_remove(struct platform_device *dev)
 {
 	struct cros_ec_pwm_device *ec_pwm = platform_get_drvdata(dev);
 	struct pwm_chip *chip = &ec_pwm->chip;
 
 	pwmchip_remove(chip);
-
-	return 0;
 }
 
 #ifdef CONFIG_OF
@@ -349,7 +347,7 @@ MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
 
 static struct platform_driver cros_ec_pwm_driver = {
 	.probe = cros_ec_pwm_probe,
-	.remove = cros_ec_pwm_remove,
+	.remove_new = cros_ec_pwm_remove,
 	.driver = {
 		.name = "cros-ec-pwm",
 		.of_match_table = of_match_ptr(cros_ec_pwm_of_match),
-- 
2.39.1

Re: [PATCH 09/30] pwm: cros-ec: Convert to platform remove callback returning void

[Guenter Roeck]

On Fri, Mar 3, 2023 at 10:55 AM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> 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 (mostly) ignored
> 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.
>
> 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: Guenter Roeck <groeck@chromium.org>

> ---
>  drivers/pwm/pwm-cros-ec.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
> index 86df6702cb83..90afce212fb0 100644
> --- a/drivers/pwm/pwm-cros-ec.c
> +++ b/drivers/pwm/pwm-cros-ec.c
> @@ -328,14 +328,12 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
>         return ret;
>  }
>
> -static int cros_ec_pwm_remove(struct platform_device *dev)
> +static void cros_ec_pwm_remove(struct platform_device *dev)
>  {
>         struct cros_ec_pwm_device *ec_pwm = platform_get_drvdata(dev);
>         struct pwm_chip *chip = &ec_pwm->chip;
>
>         pwmchip_remove(chip);
> -
> -       return 0;
>  }
>
>  #ifdef CONFIG_OF
> @@ -349,7 +347,7 @@ MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
>
>  static struct platform_driver cros_ec_pwm_driver = {
>         .probe = cros_ec_pwm_probe,
> -       .remove = cros_ec_pwm_remove,
> +       .remove_new = cros_ec_pwm_remove,
>         .driver = {
>                 .name = "cros-ec-pwm",
>                 .of_match_table = of_match_ptr(cros_ec_pwm_of_match),
> --
> 2.39.1
>

Re: [PATCH 00/30] pwm: Convert to platform remove callback returning void

[patchwork-bot+chrome-platform]

Hello:

This patch was applied to chrome-platform/linux.git (for-kernelci)
by Thierry Reding <thierry.reding@gmail.com>:

On Fri,  3 Mar 2023 19:54:15 +0100 you wrote:
> Hello,
> 
> this patch series adapts the platform drivers below drivers/pwm to use
> the .remove_new() callback. 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 a resource leak.
> 
> [...]

Here is the summary with links:
  - [09/30] pwm: cros-ec: Convert to platform remove callback returning void
    https://git.kernel.org/chrome-platform/c/159a61a7b5b0

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH 00/30] pwm: Convert to platform remove callback returning void

[patchwork-bot+chrome-platform]

Hello:

This patch was applied to chrome-platform/linux.git (for-next)
by Thierry Reding <thierry.reding@gmail.com>:

On Fri,  3 Mar 2023 19:54:15 +0100 you wrote:
> Hello,
> 
> this patch series adapts the platform drivers below drivers/pwm to use
> the .remove_new() callback. 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 a resource leak.
> 
> [...]

Here is the summary with links:
  - [09/30] pwm: cros-ec: Convert to platform remove callback returning void
    https://git.kernel.org/chrome-platform/c/159a61a7b5b0

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html