diff mbox series

[1/3] thermal: devfreq: Simplify expression

Message ID 232171cd9d89c2179e10e1f2aed71ad7fc1f7872.1486376756.git.viresh.kumar@linaro.org
State Accepted
Commit a4e49c9bc98d099b2a19933b9da55cd0ad1da421
Headers show
Series [1/3] thermal: devfreq: Simplify expression | expand

Commit Message

Viresh Kumar Feb. 6, 2017, 10:26 a.m. UTC
There is no need to check for IS_ERR() as we are looking for a very
particular error value here. Drop the first check.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 drivers/thermal/devfreq_cooling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.7.1.410.g6faf27b

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Comments

Rafael J. Wysocki Feb. 6, 2017, 12:02 p.m. UTC | #1
On Monday, February 06, 2017 03:56:28 PM Viresh Kumar wrote:
> It is possible for dev_pm_opp_find_freq_exact() to return errors. It was

> all fine earlier as dev_pm_opp_get_voltage() had a check within it to

> check for invalid OPPs, but dev_pm_opp_put() doesn't have any similar

> checks and the callers need to make sure OPP is valid before calling

> them.

> 

> Also update the later dev_warn_ratelimited() to not print the error

> message as the OPP is guaranteed to be valid now.

> 

> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> ---

>  drivers/thermal/cpu_cooling.c | 11 +++++++++--

>  1 file changed, 9 insertions(+), 2 deletions(-)

> 

> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c

> index 85fdbf762fa0..9534540434e2 100644

> --- a/drivers/thermal/cpu_cooling.c

> +++ b/drivers/thermal/cpu_cooling.c

> @@ -431,13 +431,20 @@ static int get_static_power(struct cpufreq_cooling_device *cpufreq_device,

>  

>  	opp = dev_pm_opp_find_freq_exact(cpufreq_device->cpu_dev, freq_hz,

>  					 true);

> +	if (IS_ERR(opp)) {

> +		dev_warn_ratelimited(cpufreq_device->cpu_dev,

> +				     "Failed to find OPP for frequency %lu: %ld\n",

> +				     freq_hz, PTR_ERR(opp));


I'm quite unconvinced about the WARN level of these messages.

They seem to be mostly useful for the people who provide device trees for
platforms (ie. system integrators).  If users see them, there is not much
they can do to fix the problem by themselves and the hardware is OK,
actually.

> +		return -EINVAL;

> +	}

> +

>  	voltage = dev_pm_opp_get_voltage(opp);

>  	dev_pm_opp_put(opp);

>  

>  	if (voltage == 0) {

>  		dev_warn_ratelimited(cpufreq_device->cpu_dev,

> -				     "Failed to get voltage for frequency %lu: %ld\n",

> -				     freq_hz, IS_ERR(opp) ? PTR_ERR(opp) : 0);

> +				     "Failed to get voltage for frequency %lu\n",

> +				     freq_hz);

>  		return -EINVAL;

>  	}

>  


Thanks,
Rafael

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Viresh Kumar Feb. 7, 2017, 3:58 a.m. UTC | #2
On 06-02-17, 13:02, Rafael J. Wysocki wrote:
> On Monday, February 06, 2017 03:56:28 PM Viresh Kumar wrote:

> > It is possible for dev_pm_opp_find_freq_exact() to return errors. It was

> > all fine earlier as dev_pm_opp_get_voltage() had a check within it to

> > check for invalid OPPs, but dev_pm_opp_put() doesn't have any similar

> > checks and the callers need to make sure OPP is valid before calling

> > them.

> > 

> > Also update the later dev_warn_ratelimited() to not print the error

> > message as the OPP is guaranteed to be valid now.

> > 

> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> > ---

> >  drivers/thermal/cpu_cooling.c | 11 +++++++++--

> >  1 file changed, 9 insertions(+), 2 deletions(-)

> > 

> > diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c

> > index 85fdbf762fa0..9534540434e2 100644

> > --- a/drivers/thermal/cpu_cooling.c

> > +++ b/drivers/thermal/cpu_cooling.c

> > @@ -431,13 +431,20 @@ static int get_static_power(struct cpufreq_cooling_device *cpufreq_device,

> >  

> >  	opp = dev_pm_opp_find_freq_exact(cpufreq_device->cpu_dev, freq_hz,

> >  					 true);

> > +	if (IS_ERR(opp)) {

> > +		dev_warn_ratelimited(cpufreq_device->cpu_dev,

> > +				     "Failed to find OPP for frequency %lu: %ld\n",

> > +				     freq_hz, PTR_ERR(opp));

> 

> I'm quite unconvinced about the WARN level of these messages.

> 

> They seem to be mostly useful for the people who provide device trees for

> platforms (ie. system integrators).  If users see them, there is not much

> they can do to fix the problem by themselves and the hardware is OK,

> actually.


Sure. I just wanted to keep it consistent within the function.

-- 
viresh
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diff mbox series

Patch

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
index ba7a5cd994dc..cf71550b9d00 100644
--- a/drivers/thermal/devfreq_cooling.c
+++ b/drivers/thermal/devfreq_cooling.c
@@ -222,7 +222,7 @@  get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq)
 		return 0;
 
 	opp = dev_pm_opp_find_freq_exact(dev, freq, true);
-	if (IS_ERR(opp) && (PTR_ERR(opp) == -ERANGE))
+	if (PTR_ERR(opp) == -ERANGE)
 		opp = dev_pm_opp_find_freq_exact(dev, freq, false);
 
 	voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */