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[1/3] spi: mt65xx: Properly handle failures in .remove()

Message ID 20230309094704.2568531-2-u.kleine-koenig@pengutronix.de (mailing list archive)
State Superseded
Headers show
Series spi: mt65xx: Convert to platform remove callback returning void | expand

Commit Message

Uwe Kleine-König March 9, 2023, 9:47 a.m. UTC
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.

There wasn't a real problem because if pm runtime resume failed the only
step missing was pm_runtime_disable() which isn't an issue.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/spi/spi-mt65xx.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

Comments

AngeloGioacchino Del Regno March 9, 2023, 11 a.m. UTC | #1
Il 09/03/23 10:47, Uwe Kleine-König ha scritto:
> 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.
> 
> There wasn't a real problem because if pm runtime resume failed the only
> step missing was pm_runtime_disable() which isn't an issue.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>   drivers/spi/spi-mt65xx.c | 21 +++++++++++++--------
>   1 file changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
> index 9eab6c20dbc5..b1cf7bbb2c08 100644
> --- a/drivers/spi/spi-mt65xx.c
> +++ b/drivers/spi/spi-mt65xx.c
> @@ -1275,15 +1275,20 @@ static int mtk_spi_remove(struct platform_device *pdev)
>   	struct mtk_spi *mdata = spi_master_get_devdata(master);
>   	int ret;
>   
> -	ret = pm_runtime_resume_and_get(&pdev->dev);
> -	if (ret < 0)
> -		return ret;
> -
> -	mtk_spi_reset(mdata);
> +	ret = pm_runtime_get_sync(&pdev->dev);

> +	/*
> +	 * If pm runtime resume failed, clks are disabled and unprepared. So
> +	 * don't access the hardware and skip clk unpreparing.
> +	 */

This comment is counter-intuitive: you're saying in words "if this failed" but
in code "if this didn't fail".

Please, either invert the branch so that it looks either like

/* if negative */
if (negative) warn
else /* positive */

or like

if (ret >= 0) {
	do_things()
} else {
	/* if it failed ... */
	warn
}

Functionally, though, looks good to me.

Cheers,
Angelo
diff mbox series

Patch

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 9eab6c20dbc5..b1cf7bbb2c08 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -1275,15 +1275,20 @@  static int mtk_spi_remove(struct platform_device *pdev)
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 	int ret;
 
-	ret = pm_runtime_resume_and_get(&pdev->dev);
-	if (ret < 0)
-		return ret;
-
-	mtk_spi_reset(mdata);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	/*
+	 * If pm runtime resume failed, clks are disabled and unprepared. So
+	 * don't access the hardware and skip clk unpreparing.
+	 */
+	if (ret >= 0) {
+		mtk_spi_reset(mdata);
 
-	if (mdata->dev_comp->no_need_unprepare) {
-		clk_unprepare(mdata->spi_clk);
-		clk_unprepare(mdata->spi_hclk);
+		if (mdata->dev_comp->no_need_unprepare) {
+			clk_unprepare(mdata->spi_clk);
+			clk_unprepare(mdata->spi_hclk);
+		}
+	} else {
+		dev_warn(&pdev->dev, "Failed to resume hardware (%pe)\n", ERR_PTR(ret));
 	}
 
 	pm_runtime_put_noidle(&pdev->dev);