diff mbox series

[v2,25/61] mmc: f-sdh30: Convert to platform remove callback returning void

Message ID 20230726040041.26267-25-frank.li@vivo.com
State New
Headers
Series [v2,01/61] mmc: sunxi: Convert to platform remove callback returning void |

Commit Message

李扬韬 July 26, 2023, 4 a.m. UTC 
  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.

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/mmc/host/sdhci_f_sdh30.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

Comments

Adrian Hunter July 26, 2023, 6:39 a.m. UTC | #1 
On 26/07/23 07:00, Yangtao Li 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.
> 
> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Signed-off-by: Yangtao Li <frank.li@vivo.com>
> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci_f_sdh30.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci_f_sdh30.c b/drivers/mmc/host/sdhci_f_sdh30.c
> index b01ffb4d0973..840084ee72e6 100644
> --- a/drivers/mmc/host/sdhci_f_sdh30.c
> +++ b/drivers/mmc/host/sdhci_f_sdh30.c
> @@ -206,7 +206,7 @@ static int sdhci_f_sdh30_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -static int sdhci_f_sdh30_remove(struct platform_device *pdev)
> +static void sdhci_f_sdh30_remove(struct platform_device *pdev)
>  {
>  	struct sdhci_host *host = platform_get_drvdata(pdev);
>  	struct f_sdhost_priv *priv = sdhci_f_sdhost_priv(host);
> @@ -216,8 +216,6 @@ static int sdhci_f_sdh30_remove(struct platform_device *pdev)
>  	clk_disable_unprepare(priv->clk_iface);
>  
>  	sdhci_pltfm_unregister(pdev);
> -
> -	return 0;
>  }
>  
>  #ifdef CONFIG_OF
> @@ -245,8 +243,8 @@ static struct platform_driver sdhci_f_sdh30_driver = {
>  		.acpi_match_table = ACPI_PTR(f_sdh30_acpi_ids),
>  		.pm	= &sdhci_pltfm_pmops,
>  	},
> -	.probe	= sdhci_f_sdh30_probe,
> -	.remove	= sdhci_f_sdh30_remove,
> +	.probe = sdhci_f_sdh30_probe,
> +	.remove_new = sdhci_f_sdh30_remove,
>  };
>  
>  module_platform_driver(sdhci_f_sdh30_driver);
Uwe Kleine-König July 26, 2023, 6:53 a.m. UTC | #2 
On Wed, Jul 26, 2023 at 12:00:05PM +0800, Yangtao Li 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.
> 
> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Signed-off-by: Yangtao Li <frank.li@vivo.com>
> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/mmc/host/sdhci_f_sdh30.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci_f_sdh30.c b/drivers/mmc/host/sdhci_f_sdh30.c
> index b01ffb4d0973..840084ee72e6 100644
> --- a/drivers/mmc/host/sdhci_f_sdh30.c
> +++ b/drivers/mmc/host/sdhci_f_sdh30.c
> @@ -206,7 +206,7 @@ static int sdhci_f_sdh30_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -static int sdhci_f_sdh30_remove(struct platform_device *pdev)
> +static void sdhci_f_sdh30_remove(struct platform_device *pdev)
>  {
>  	struct sdhci_host *host = platform_get_drvdata(pdev);
>  	struct f_sdhost_priv *priv = sdhci_f_sdhost_priv(host);
> @@ -216,8 +216,6 @@ static int sdhci_f_sdh30_remove(struct platform_device *pdev)
>  	clk_disable_unprepare(priv->clk_iface);
>  
>  	sdhci_pltfm_unregister(pdev);
> -
> -	return 0;
>  }

While looking in more detail into this series I noticed a problem in
this driver. (The patch is fine, and so is my Ack.)

The order of function calls in sdhci_f_sdh30_remove is wrong. It first
reasserts the reset and disables clocks and only then unregisters the
sdhci-host which should stay functional until sdhci_remove_host() (called
by sdhci_pltfm_unregister()) completes.

Best regards
Uwe
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci_f_sdh30.c b/drivers/mmc/host/sdhci_f_sdh30.c
index b01ffb4d0973..840084ee72e6 100644
--- a/drivers/mmc/host/sdhci_f_sdh30.c
+++ b/drivers/mmc/host/sdhci_f_sdh30.c
@@ -206,7 +206,7 @@  static int sdhci_f_sdh30_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int sdhci_f_sdh30_remove(struct platform_device *pdev)
+static void sdhci_f_sdh30_remove(struct platform_device *pdev)
 {
 	struct sdhci_host *host = platform_get_drvdata(pdev);
 	struct f_sdhost_priv *priv = sdhci_f_sdhost_priv(host);
@@ -216,8 +216,6 @@  static int sdhci_f_sdh30_remove(struct platform_device *pdev)
 	clk_disable_unprepare(priv->clk_iface);
 
 	sdhci_pltfm_unregister(pdev);
-
-	return 0;
 }
 
 #ifdef CONFIG_OF
@@ -245,8 +243,8 @@  static struct platform_driver sdhci_f_sdh30_driver = {
 		.acpi_match_table = ACPI_PTR(f_sdh30_acpi_ids),
 		.pm	= &sdhci_pltfm_pmops,
 	},
-	.probe	= sdhci_f_sdh30_probe,
-	.remove	= sdhci_f_sdh30_remove,
+	.probe = sdhci_f_sdh30_probe,
+	.remove_new = sdhci_f_sdh30_remove,
 };
 
 module_platform_driver(sdhci_f_sdh30_driver);