linux-kernel - Re: [PATCH v2 60/61] mmc: sdhci_am654: Properly handle failures in .remove()

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Message-ID: <20230726070234.4im3v23qbago763b@pengutronix.de>
Date:   Wed, 26 Jul 2023 09:02:34 +0200
From:   Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
To:     Yangtao Li <frank.li@...o.com>
Cc:     Adrian Hunter <adrian.hunter@...el.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 60/61] mmc: sdhci_am654: Properly handle failures in
 .remove()

On Wed, Jul 26, 2023 at 12:00:40PM +0800, Yangtao Li wrote:
> Returning an error code in a platform driver's remove function is wrong
> most of the time and there is an effort to make the callback return
> void. To prepare this rework the function not to exit early.
> 
> Cc: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
> Signed-off-by: Yangtao Li <frank.li@...o.com>
> ---
>  drivers/mmc/host/sdhci_am654.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
> index 7cdf0f54e3a5..abe83736d396 100644
> --- a/drivers/mmc/host/sdhci_am654.c
> +++ b/drivers/mmc/host/sdhci_am654.c
> @@ -873,8 +873,7 @@ static int sdhci_am654_remove(struct platform_device *pdev)
>  	int ret;
>  
>  	ret = pm_runtime_resume_and_get(&pdev->dev);
> -	if (ret < 0)
> -		return ret;
> +	WARN_ON(ret < 0);

You must use pm_runtime_get_sync() instead of
pm_runtime_resume_and_get() here because in the error case
pm_runtime_resume_and_get() already calls pm_runtime_put_noidle() which
is repeated here in this driver.

Also WARN_ON is a pretty big hammer, I'd go with a dev_err() instead.

Best regards
Uwe

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

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