[PATCH 00/15] memory: Convert to platform remove callback returning void

[PATCH 00/15] memory: Convert to platform remove callback returning void

[Uwe Kleine-König]

Hello,

this series converts the platform drivers below drivers/memory to make
use of .remove_new. See commit 5c5a7680e67b ("platform: Provide a remove
callback that returns no value") for an extended explanation and the
eventual goal. The TL;DR; is to make it harder for driver authors to
leak resources without noticing.

This is merge window material. All patches are pairwise independent of
each other so they can be applied individually. Still it would be great
to let them go in all together.

Best regards
Uwe

Uwe Kleine-König (15):
  memory: brcmstb_dpfe: Convert to platform remove callback returning void
  memory: brcmstb_memc: Convert to platform remove callback returning void
  memory: emif: Convert to platform remove callback returning void
  memory: fsl-corenet-cf: Convert to platform remove callback returning void
  memory: fsl_ifc: Convert to platform remove callback returning void
  memory: jz4780-nemc: Convert to platform remove callback returning void
  memory: mtk-smi: Convert to platform remove callback returning void
  memory: omap-gpmc: Convert to platform remove callback returning void
  memory: renesas-rpc-if: Convert to platform remove callback returning void
  memory: exynos5422-dmc: Convert to platform remove callback returning void
  memory: stm32-fmc2-ebi: Convert to platform remove callback returning void
  memory: tegra186-emc: Convert to platform remove callback returning void
  memory: tegra210-emc: Convert to platform remove callback returning void
  memory: ti-aemif: Convert to platform remove callback returning void
  memory: ti-emif-pm: Convert to platform remove callback returning void

 drivers/memory/brcmstb_dpfe.c            |  6 ++----
 drivers/memory/brcmstb_memc.c            |  6 ++----
 drivers/memory/emif.c                    |  6 ++----
 drivers/memory/fsl-corenet-cf.c          |  6 ++----
 drivers/memory/fsl_ifc.c                 |  6 ++----
 drivers/memory/jz4780-nemc.c             |  5 ++---
 drivers/memory/mtk-smi.c                 | 10 ++++------
 drivers/memory/omap-gpmc.c               |  6 ++----
 drivers/memory/renesas-rpc-if.c          |  6 ++----
 drivers/memory/samsung/exynos5422-dmc.c  |  6 ++----
 drivers/memory/stm32-fmc2-ebi.c          |  6 ++----
 drivers/memory/tegra/tegra186-emc.c      |  6 ++----
 drivers/memory/tegra/tegra210-emc-core.c |  6 ++----
 drivers/memory/ti-aemif.c                |  5 ++---
 drivers/memory/ti-emif-pm.c              |  6 ++----
 15 files changed, 32 insertions(+), 60 deletions(-)

base-commit: 17cb8a20bde66a520a2ca7aad1063e1ce7382240
-- 
2.42.0

[PATCH 06/15] memory: jz4780-nemc: 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/memory/jz4780-nemc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/memory/jz4780-nemc.c b/drivers/memory/jz4780-nemc.c
index e5a93e7da15f..fb6db2ffe71b 100644
--- a/drivers/memory/jz4780-nemc.c
+++ b/drivers/memory/jz4780-nemc.c
@@ -384,12 +384,11 @@ static int jz4780_nemc_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int jz4780_nemc_remove(struct platform_device *pdev)
+static void jz4780_nemc_remove(struct platform_device *pdev)
 {
 	struct jz4780_nemc *nemc = platform_get_drvdata(pdev);
 
 	clk_disable_unprepare(nemc->clk);
-	return 0;
 }
 
 static const struct jz_soc_info jz4740_soc_info = {
@@ -408,7 +407,7 @@ static const struct of_device_id jz4780_nemc_dt_match[] = {
 
 static struct platform_driver jz4780_nemc_driver = {
 	.probe		= jz4780_nemc_probe,
-	.remove		= jz4780_nemc_remove,
+	.remove_new	= jz4780_nemc_remove,
 	.driver	= {
 		.name	= "jz4780-nemc",
 		.of_match_table = of_match_ptr(jz4780_nemc_dt_match),
-- 
2.42.0

Re: [PATCH 06/15] memory: jz4780-nemc: Convert to platform remove callback returning void

[Paul Cercueil]

Hi,

Le dimanche 17 décembre 2023 à 15:29 +0100, Uwe Kleine-König a écrit :
> 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>

Acked-by: Paul Cercueil <paul@crapouillou.net>

Cheers,
-Paul

> ---
>  drivers/memory/jz4780-nemc.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/memory/jz4780-nemc.c b/drivers/memory/jz4780-
> nemc.c
> index e5a93e7da15f..fb6db2ffe71b 100644
> --- a/drivers/memory/jz4780-nemc.c
> +++ b/drivers/memory/jz4780-nemc.c
> @@ -384,12 +384,11 @@ static int jz4780_nemc_probe(struct
> platform_device *pdev)
>  	return 0;
>  }
>  
> -static int jz4780_nemc_remove(struct platform_device *pdev)
> +static void jz4780_nemc_remove(struct platform_device *pdev)
>  {
>  	struct jz4780_nemc *nemc = platform_get_drvdata(pdev);
>  
>  	clk_disable_unprepare(nemc->clk);
> -	return 0;
>  }
>  
>  static const struct jz_soc_info jz4740_soc_info = {
> @@ -408,7 +407,7 @@ static const struct of_device_id
> jz4780_nemc_dt_match[] = {
>  
>  static struct platform_driver jz4780_nemc_driver = {
>  	.probe		= jz4780_nemc_probe,
> -	.remove		= jz4780_nemc_remove,
> +	.remove_new	= jz4780_nemc_remove,
>  	.driver	= {
>  		.name	= "jz4780-nemc",
>  		.of_match_table =
> of_match_ptr(jz4780_nemc_dt_match),

Re: [PATCH 00/15] memory: Convert to platform remove callback returning void

[Krzysztof Kozlowski]

On Sun, 17 Dec 2023 15:29:26 +0100, Uwe Kleine-König wrote:
> this series converts the platform drivers below drivers/memory to make
> use of .remove_new. See commit 5c5a7680e67b ("platform: Provide a remove
> callback that returns no value") for an extended explanation and the
> eventual goal. The TL;DR; is to make it harder for driver authors to
> leak resources without noticing.
> 
> This is merge window material. All patches are pairwise independent of
> each other so they can be applied individually. Still it would be great
> to let them go in all together.
> 
> [...]

Applied, thanks!

[01/15] memory: brcmstb_dpfe: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/431187eadbc7b0f2650d4e55111b3fff4720f867
[02/15] memory: brcmstb_memc: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/f7754712ad6094de5be18674777b265ed4db2f45
[03/15] memory: emif: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/c8a53461990cb697ca494d6671fab9e196d20ce4
[04/15] memory: fsl-corenet-cf: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/021d044b0f9c9a09aa2f778e876e467a8810fb4a
[05/15] memory: fsl_ifc: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/f17130855d51f24563a24cd957add769ad59eee9
[06/15] memory: jz4780-nemc: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/9024fbbd77b4d73279bbbe2c748a4e4b414d50cc
[07/15] memory: mtk-smi: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/08c1aeaa45ce0fd18912e92c6705586c8aa5240f
[08/15] memory: omap-gpmc: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/6a4edb1a4f61e28cc127cd06c470ce3599ee0d9c
[09/15] memory: renesas-rpc-if: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/961abc9f7d6771e8f13db1f4d8b0ffff3f0f41a4
[10/15] memory: exynos5422-dmc: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/8013408e4912fb7e469bb8b14fd3a5c956257eec
[11/15] memory: stm32-fmc2-ebi: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/1455b6b0c83132960826d0e527a79a355e096a80
[12/15] memory: tegra186-emc: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/dcefa0368458e9e20642dbd2608adae6b22e6464
[13/15] memory: tegra210-emc: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/622fa819a2f0f3e6d8322a0b6d3177302ae937b6
[14/15] memory: ti-aemif: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/7852eb8c8ac7e0164b43cc5f8d8245cc3a037620
[15/15] memory: ti-emif-pm: Convert to platform remove callback returning void
        https://git.kernel.org/krzk/linux-mem-ctrl/c/365fcc03b6321f36eb7cbda8baa737238c387907

Best regards,
-- 
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Re: [PATCH 00/15] memory: Convert to platform remove callback returning void

[Krzysztof Kozlowski]

On 17/12/2023 15:29, Uwe Kleine-König wrote:
> Hello,
> 
> this series converts the platform drivers below drivers/memory to make
> use of .remove_new. See commit 5c5a7680e67b ("platform: Provide a remove
> callback that returns no value") for an extended explanation and the
> eventual goal. The TL;DR; is to make it harder for driver authors to
> leak resources without noticing.

Thanks, applied.
It is however very late in the cycle, so there is a chance this will
miss the merge window. If this happens, I will keep it for the next
cycle (no need for resending).

Best regards,
Krzysztof