2023-07-13 08:39:03

by 李扬韬

[permalink] [raw]
Subject: [PATCH 16/58] mmc: rtsx_pci: Convert to platform remove callback returning void

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 <[email protected]>
Signed-off-by: Yangtao Li <[email protected]>
---
drivers/mmc/host/rtsx_pci_sdmmc.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index 8098726dcc0b..5465a7225df4 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -1523,14 +1523,14 @@ static int rtsx_pci_sdmmc_drv_probe(struct platform_device *pdev)
return 0;
}

-static int rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
+static void rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
{
struct realtek_pci_sdmmc *host = platform_get_drvdata(pdev);
struct rtsx_pcr *pcr;
struct mmc_host *mmc;

if (!host)
- return 0;
+ return;

pcr = host->pcr;
pcr->slots[RTSX_SD_CARD].p_dev = NULL;
@@ -1566,8 +1566,6 @@ static int rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)

dev_dbg(&(pdev->dev),
": Realtek PCI-E SDMMC controller has been removed\n");
-
- return 0;
}

static const struct platform_device_id rtsx_pci_sdmmc_ids[] = {
@@ -1581,7 +1579,7 @@ MODULE_DEVICE_TABLE(platform, rtsx_pci_sdmmc_ids);

static struct platform_driver rtsx_pci_sdmmc_driver = {
.probe = rtsx_pci_sdmmc_drv_probe,
- .remove = rtsx_pci_sdmmc_drv_remove,
+ .remove_new = rtsx_pci_sdmmc_drv_remove,
.id_table = rtsx_pci_sdmmc_ids,
.driver = {
.name = DRV_NAME_RTSX_PCI_SDMMC,
--
2.39.0



2023-07-13 09:27:38

by Uwe Kleine-König

[permalink] [raw]
Subject: Re: [PATCH 16/58] mmc: rtsx_pci: Convert to platform remove callback returning void

On Thu, Jul 13, 2023 at 04:07:25PM +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-K?nig <[email protected]>
> Signed-off-by: Yangtao Li <[email protected]>
> ---
> drivers/mmc/host/rtsx_pci_sdmmc.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
> index 8098726dcc0b..5465a7225df4 100644
> --- a/drivers/mmc/host/rtsx_pci_sdmmc.c
> +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
> @@ -1523,14 +1523,14 @@ static int rtsx_pci_sdmmc_drv_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
> +static void rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
> {
> struct realtek_pci_sdmmc *host = platform_get_drvdata(pdev);
> struct rtsx_pcr *pcr;
> struct mmc_host *mmc;
>
> if (!host)
> - return 0;
> + return;

If host is NULL, there is a problem. While sometimes (rarely) driver
maintainers object, I usually remove these, see for example
3d82dca0f27ac5a0bfbbce439bba5c6452f3b7da.

> pcr = host->pcr;
> pcr->slots[RTSX_SD_CARD].p_dev = NULL;

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | https://www.pengutronix.de/ |


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