2022-03-02 09:08:18

by Jiasheng Jiang

Subject: [PATCH] misc: atmel-ssc: Handle error for clk_prepare_enable

As the potential failure of the clk_prepare_enable(),
it should be better to check it and return error if fails.

Fixes: eb1f2930609b ("Driver for the Atmel on-chip SSC on AT32AP and AT91")
Signed-off-by: Jiasheng Jiang <[email protected]>
---
drivers/misc/atmel-ssc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
index d6cd5537126c..c76ca234af4b 100644
--- a/drivers/misc/atmel-ssc.c
+++ b/drivers/misc/atmel-ssc.c
@@ -192,6 +192,7 @@ static int ssc_probe(struct platform_device *pdev)
struct resource *regs;
struct ssc_device *ssc;
const struct atmel_ssc_platform_data *plat_dat;
+ int ret;

ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
if (!ssc) {
@@ -226,7 +227,10 @@ static int ssc_probe(struct platform_device *pdev)
}

/* disable all interrupts */
- clk_prepare_enable(ssc->clk);
+ ret = clk_prepare_enable(ssc->clk);
+ if (ret)
+ return ret;
+
ssc_writel(ssc->regs, IDR, -1);
ssc_readl(ssc->regs, SR);
clk_disable_unprepare(ssc->clk);
--
2.25.1

2022-03-02 15:14:07

by Alexandre Belloni

Subject: Re: [PATCH] misc: atmel-ssc: Handle error for clk_prepare_enable

On 02/03/2022 16:43:19+0800, Jiasheng Jiang wrote:
> As the potential failure of the clk_prepare_enable(),
> it should be better to check it and return error if fails.
>

this will never ever fail, this patch doesn't fix any actual issue

> Fixes: eb1f2930609b ("Driver for the Atmel on-chip SSC on AT32AP and AT91")
> Signed-off-by: Jiasheng Jiang <[email protected]>
> ---
> drivers/misc/atmel-ssc.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
> index d6cd5537126c..c76ca234af4b 100644
> --- a/drivers/misc/atmel-ssc.c
> +++ b/drivers/misc/atmel-ssc.c
> @@ -192,6 +192,7 @@ static int ssc_probe(struct platform_device *pdev)
> struct resource *regs;
> struct ssc_device *ssc;
> const struct atmel_ssc_platform_data *plat_dat;
> + int ret;
>
> ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
> if (!ssc) {
> @@ -226,7 +227,10 @@ static int ssc_probe(struct platform_device *pdev)
> }
>
> /* disable all interrupts */
> - clk_prepare_enable(ssc->clk);
> + ret = clk_prepare_enable(ssc->clk);
> + if (ret)
> + return ret;
> +
> ssc_writel(ssc->regs, IDR, -1);
> ssc_readl(ssc->regs, SR);
> clk_disable_unprepare(ssc->clk);
> --
> 2.25.1
>

--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com