cpufreq: Fix an IS_ERR() vs NULL bug in spear1340_set_cpu_rate()

[PATCH] cpufreq: Fix an IS_ERR() vs NULL bug in spear1340_set_cpu_rate()

Posted by Dan Carpenter 2 weeks, 1 day ago

The clk_get_parent() function doesn't return error pointers, it returns
NULL on error.  Update the error checking to match.

Fixes: 420993221175 ("cpufreq: SPEAr: Add CPUFreq driver")
Signed-off-by: Dan Carpenter <error27@gmail.com>
---
 drivers/cpufreq/spear-cpufreq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
index 81a0780b2ebf..ffe5eda82f0b 100644
--- a/drivers/cpufreq/spear-cpufreq.c
+++ b/drivers/cpufreq/spear-cpufreq.c
@@ -79,9 +79,9 @@ static int spear1340_set_cpu_rate(struct clk *sys_pclk, unsigned long newfreq)
 	int ret = 0;
 
 	sys_clk = clk_get_parent(spear_cpufreq.clk);
-	if (IS_ERR(sys_clk)) {
+	if (!sys_clk) {
 		pr_err("failed to get cpu's parent (sys) clock\n");
-		return PTR_ERR(sys_clk);
+		return -EINVAL;
 	}
 
 	/* Set the rate of the source clock before changing the parent */
-- 
2.53.0

Re: [PATCH] cpufreq: Fix an IS_ERR() vs NULL bug in spear1340_set_cpu_rate()

Posted by Zhongqiu Han 1 week, 6 days ago

On 7/11/2026 3:34 AM, Dan Carpenter wrote:
> The clk_get_parent() function doesn't return error pointers, it returns
> NULL on error.  Update the error checking to match.
> 
> Fixes: 420993221175 ("cpufreq: SPEAr: Add CPUFreq driver")
> Signed-off-by: Dan Carpenter <error27@gmail.com>

Nice catch, thanks for the fix.

Nit: the subject is too generic and can be misread as a cpufreq core
fix. It is better to scope it to the driver, e.g. "cpufreq: spear: ...".

With that:

Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>


> ---
>   drivers/cpufreq/spear-cpufreq.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
> index 81a0780b2ebf..ffe5eda82f0b 100644
> --- a/drivers/cpufreq/spear-cpufreq.c
> +++ b/drivers/cpufreq/spear-cpufreq.c
> @@ -79,9 +79,9 @@ static int spear1340_set_cpu_rate(struct clk *sys_pclk, unsigned long newfreq)
>   	int ret = 0;
>   
>   	sys_clk = clk_get_parent(spear_cpufreq.clk);
> -	if (IS_ERR(sys_clk)) {
> +	if (!sys_clk) {
>   		pr_err("failed to get cpu's parent (sys) clock\n");
> -		return PTR_ERR(sys_clk);
> +		return -EINVAL;
>   	}
>   
>   	/* Set the rate of the source clock before changing the parent */


-- 
Thx and BRs,
Zhongqiu Han

Re: [PATCH] cpufreq: Fix an IS_ERR() vs NULL bug in spear1340_set_cpu_rate()

Posted by Dan Carpenter 1 week, 5 days ago

On Sun, Jul 12, 2026 at 09:30:16PM +0800, Zhongqiu Han wrote:
> On 7/11/2026 3:34 AM, Dan Carpenter wrote:
> > The clk_get_parent() function doesn't return error pointers, it returns
> > NULL on error.  Update the error checking to match.
> > 
> > Fixes: 420993221175 ("cpufreq: SPEAr: Add CPUFreq driver")
> > Signed-off-by: Dan Carpenter <error27@gmail.com>
> 
> Nice catch, thanks for the fix.
> 
> Nit: the subject is too generic and can be misread as a cpufreq core
> fix. It is better to scope it to the driver, e.g. "cpufreq: spear: ...".
> 

Oops.  Sorry.

regards,
dan carpenter

Re: [PATCH] cpufreq: Fix an IS_ERR() vs NULL bug in spear1340_set_cpu_rate()

Posted by Viresh Kumar 1 week, 5 days ago

On 12-07-26, 21:30, Zhongqiu Han wrote:
> On 7/11/2026 3:34 AM, Dan Carpenter wrote:
> > The clk_get_parent() function doesn't return error pointers, it returns
> > NULL on error.  Update the error checking to match.

origin/master:include/linux/clk.h

/**
 * clk_get_parent - get the parent clock source for this clock
 * @clk: clock source
 *
 * Returns struct clk corresponding to parent clock source, or
 * valid IS_ERR() condition containing errno.
 */
struct clk *clk_get_parent(struct clk *clk);

I think this is the source of the confusion.

> > 
> > Fixes: 420993221175 ("cpufreq: SPEAr: Add CPUFreq driver")
> > Signed-off-by: Dan Carpenter <error27@gmail.com>
> 
> Nice catch, thanks for the fix.
> 
> Nit: the subject is too generic and can be misread as a cpufreq core
> fix. It is better to scope it to the driver, e.g. "cpufreq: spear: ...".

Right.

-- 
viresh

Re: [PATCH] cpufreq: Fix an IS_ERR() vs NULL bug in spear1340_set_cpu_rate()

Posted by Dan Carpenter 1 week, 5 days ago

On Mon, Jul 13, 2026 at 09:31:12AM +0530, Viresh Kumar wrote:
> On 12-07-26, 21:30, Zhongqiu Han wrote:
> > On 7/11/2026 3:34 AM, Dan Carpenter wrote:
> > > The clk_get_parent() function doesn't return error pointers, it returns
> > > NULL on error.  Update the error checking to match.
> 
> origin/master:include/linux/clk.h
> 
> /**
>  * clk_get_parent - get the parent clock source for this clock
>  * @clk: clock source
>  *
>  * Returns struct clk corresponding to parent clock source, or
>  * valid IS_ERR() condition containing errno.
>  */
> struct clk *clk_get_parent(struct clk *clk);
> 
> I think this is the source of the confusion.
> 

I'll send a separate patch to update that documentation.

regards,
dan carpenter