cpufreq: cpufreq-dt: avoid uninitialized variable warnings:
diff mbox

Message ID 1453736756-1959377-1-git-send-email-arnd@arndb.de
State Accepted, archived
Delegated to: Rafael Wysocki
Headers show

Commit Message

Arnd Bergmann Jan. 25, 2016, 3:45 p.m. UTC
gcc warns quite a bit about values returned from allocate_resources()
in cpufreq-dt.c:

cpufreq-dt.c: In function 'cpufreq_init':
cpufreq-dt.c:327:6: error: 'cpu_dev' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:197:17: note: 'cpu_dev' was declared here
cpufreq-dt.c:376:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:199:14: note: 'cpu_clk' was declared here
cpufreq-dt.c: In function 'dt_cpufreq_probe':
cpufreq-dt.c:461:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
cpufreq-dt.c:447:14: note: 'cpu_clk' was declared here

The problem is that it's slightly hard for gcc to follow return
codes across PTR_ERR() calls.
This patch uses explicit assignments to the "ret" variable to make
it easier for gcc to verify that the code is actually correct,
without the need to add a bogus initialization.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/cpufreq/cpufreq-dt.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

Comments

Viresh Kumar Jan. 25, 2016, 4:37 p.m. UTC | #1
On 25-01-16, 16:45, Arnd Bergmann wrote:
> gcc warns quite a bit about values returned from allocate_resources()
> in cpufreq-dt.c:
> 
> cpufreq-dt.c: In function 'cpufreq_init':
> cpufreq-dt.c:327:6: error: 'cpu_dev' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> cpufreq-dt.c:197:17: note: 'cpu_dev' was declared here
> cpufreq-dt.c:376:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> cpufreq-dt.c:199:14: note: 'cpu_clk' was declared here
> cpufreq-dt.c: In function 'dt_cpufreq_probe':
> cpufreq-dt.c:461:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> cpufreq-dt.c:447:14: note: 'cpu_clk' was declared here
> 
> The problem is that it's slightly hard for gcc to follow return
> codes across PTR_ERR() calls.
> This patch uses explicit assignments to the "ret" variable to make
> it easier for gcc to verify that the code is actually correct,
> without the need to add a bogus initialization.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/cpufreq/cpufreq-dt.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> index 9bc37c437874..0ca74d070058 100644
> --- a/drivers/cpufreq/cpufreq-dt.c
> +++ b/drivers/cpufreq/cpufreq-dt.c
> @@ -142,15 +142,16 @@ static int allocate_resources(int cpu, struct device **cdev,
>  
>  try_again:
>  	cpu_reg = regulator_get_optional(cpu_dev, reg);
> -	if (IS_ERR(cpu_reg)) {
> +	ret = PTR_ERR_OR_ZERO(cpu_reg);
> +	if (ret) {
>  		/*
>  		 * If cpu's regulator supply node is present, but regulator is
>  		 * not yet registered, we should try defering probe.
>  		 */
> -		if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
> +		if (ret == -EPROBE_DEFER) {
>  			dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n",
>  				cpu);
> -			return -EPROBE_DEFER;
> +			return ret;
>  		}
>  
>  		/* Try with "cpu-supply" */
> @@ -159,18 +160,16 @@ try_again:
>  			goto try_again;
>  		}
>  
> -		dev_dbg(cpu_dev, "no regulator for cpu%d: %ld\n",
> -			cpu, PTR_ERR(cpu_reg));
> +		dev_dbg(cpu_dev, "no regulator for cpu%d: %d\n", cpu, ret);
>  	}
>  
>  	cpu_clk = clk_get(cpu_dev, NULL);
> -	if (IS_ERR(cpu_clk)) {
> +	ret = PTR_ERR_OR_ZERO(cpu_clk);
> +	if (ret) {
>  		/* put regulator */
>  		if (!IS_ERR(cpu_reg))
>  			regulator_put(cpu_reg);
>  
> -		ret = PTR_ERR(cpu_clk);
> -
>  		/*
>  		 * If cpu's clk node is present, but clock is not yet
>  		 * registered, we should try defering probe.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Rafael J. Wysocki Jan. 27, 2016, 10:56 p.m. UTC | #2
On Monday, January 25, 2016 10:07:20 PM Viresh Kumar wrote:
> On 25-01-16, 16:45, Arnd Bergmann wrote:
> > gcc warns quite a bit about values returned from allocate_resources()
> > in cpufreq-dt.c:
> > 
> > cpufreq-dt.c: In function 'cpufreq_init':
> > cpufreq-dt.c:327:6: error: 'cpu_dev' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> > cpufreq-dt.c:197:17: note: 'cpu_dev' was declared here
> > cpufreq-dt.c:376:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> > cpufreq-dt.c:199:14: note: 'cpu_clk' was declared here
> > cpufreq-dt.c: In function 'dt_cpufreq_probe':
> > cpufreq-dt.c:461:2: error: 'cpu_clk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> > cpufreq-dt.c:447:14: note: 'cpu_clk' was declared here
> > 
> > The problem is that it's slightly hard for gcc to follow return
> > codes across PTR_ERR() calls.
> > This patch uses explicit assignments to the "ret" variable to make
> > it easier for gcc to verify that the code is actually correct,
> > without the need to add a bogus initialization.
> > 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > ---
> >  drivers/cpufreq/cpufreq-dt.c | 15 +++++++--------
> >  1 file changed, 7 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> > index 9bc37c437874..0ca74d070058 100644
> > --- a/drivers/cpufreq/cpufreq-dt.c
> > +++ b/drivers/cpufreq/cpufreq-dt.c
> > @@ -142,15 +142,16 @@ static int allocate_resources(int cpu, struct device **cdev,
> >  
> >  try_again:
> >  	cpu_reg = regulator_get_optional(cpu_dev, reg);
> > -	if (IS_ERR(cpu_reg)) {
> > +	ret = PTR_ERR_OR_ZERO(cpu_reg);
> > +	if (ret) {
> >  		/*
> >  		 * If cpu's regulator supply node is present, but regulator is
> >  		 * not yet registered, we should try defering probe.
> >  		 */
> > -		if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
> > +		if (ret == -EPROBE_DEFER) {
> >  			dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n",
> >  				cpu);
> > -			return -EPROBE_DEFER;
> > +			return ret;
> >  		}
> >  
> >  		/* Try with "cpu-supply" */
> > @@ -159,18 +160,16 @@ try_again:
> >  			goto try_again;
> >  		}
> >  
> > -		dev_dbg(cpu_dev, "no regulator for cpu%d: %ld\n",
> > -			cpu, PTR_ERR(cpu_reg));
> > +		dev_dbg(cpu_dev, "no regulator for cpu%d: %d\n", cpu, ret);
> >  	}
> >  
> >  	cpu_clk = clk_get(cpu_dev, NULL);
> > -	if (IS_ERR(cpu_clk)) {
> > +	ret = PTR_ERR_OR_ZERO(cpu_clk);
> > +	if (ret) {
> >  		/* put regulator */
> >  		if (!IS_ERR(cpu_reg))
> >  			regulator_put(cpu_reg);
> >  
> > -		ret = PTR_ERR(cpu_clk);
> > -
> >  		/*
> >  		 * If cpu's clk node is present, but clock is not yet
> >  		 * registered, we should try defering probe.
> 
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Applied, thanks!

Rafael

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Patch
diff mbox

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 9bc37c437874..0ca74d070058 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -142,15 +142,16 @@  static int allocate_resources(int cpu, struct device **cdev,
 
 try_again:
 	cpu_reg = regulator_get_optional(cpu_dev, reg);
-	if (IS_ERR(cpu_reg)) {
+	ret = PTR_ERR_OR_ZERO(cpu_reg);
+	if (ret) {
 		/*
 		 * If cpu's regulator supply node is present, but regulator is
 		 * not yet registered, we should try defering probe.
 		 */
-		if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
+		if (ret == -EPROBE_DEFER) {
 			dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n",
 				cpu);
-			return -EPROBE_DEFER;
+			return ret;
 		}
 
 		/* Try with "cpu-supply" */
@@ -159,18 +160,16 @@  try_again:
 			goto try_again;
 		}
 
-		dev_dbg(cpu_dev, "no regulator for cpu%d: %ld\n",
-			cpu, PTR_ERR(cpu_reg));
+		dev_dbg(cpu_dev, "no regulator for cpu%d: %d\n", cpu, ret);
 	}
 
 	cpu_clk = clk_get(cpu_dev, NULL);
-	if (IS_ERR(cpu_clk)) {
+	ret = PTR_ERR_OR_ZERO(cpu_clk);
+	if (ret) {
 		/* put regulator */
 		if (!IS_ERR(cpu_reg))
 			regulator_put(cpu_reg);
 
-		ret = PTR_ERR(cpu_clk);
-
 		/*
 		 * If cpu's clk node is present, but clock is not yet
 		 * registered, we should try defering probe.