[PATCH] bus: arm-ccn: Fix cpu notifier priority

[PATCH] bus: arm-ccn: Fix cpu notifier priority

[Jan Glauber]

Fix cpu priority of notifier block that was erroneously set to
return value of next statement.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/bus/arm-ccn.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 7082c72..d4a939e 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -1271,7 +1271,7 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn)
 	 * picked to have a chance to migrate events before perf is notified.
 	 */
 	ccn->dt.cpu_nb.notifier_call = arm_ccn_pmu_cpu_notifier;
-	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1,
+	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1;
 	err = register_cpu_notifier(&ccn->dt.cpu_nb);
 	if (err)
 		goto error_cpu_notifier;
-- 
1.9.1

[PATCH] bus: arm-ccn: Fix cpu notifier priority

[Pawel Moll]

On Tue, 2016-03-08 at 13:14 +0100, Jan Glauber wrote:
> Fix cpu priority of notifier block that was erroneously set to
> return value of next statement.
> 
> Signed-off-by: Jan Glauber <jglauber@cavium.com>
> ---
>  drivers/bus/arm-ccn.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
> index 7082c72..d4a939e 100644
> --- a/drivers/bus/arm-ccn.c
> +++ b/drivers/bus/arm-ccn.c
> @@ -1271,7 +1271,7 @@ static int arm_ccn_pmu_init(struct arm_ccn
> *ccn)
>  	 * picked to have a chance to migrate events before perf is
> notified.
>  	 */
>  	ccn->dt.cpu_nb.notifier_call = arm_ccn_pmu_cpu_notifier;
> -	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1,
> +	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1;
>  	err = register_cpu_notifier(&ccn->dt.cpu_nb);
>  	if (err)
>  		goto error_cpu_notifier;

Damn, of course! I have never made (or heard about) such a typo before 
- I wish the compiler warned about it :-(

By all means:

Acked-by: Pawel Moll <pawel.moll@arm.com>
Cc: <stable@vger.kernel.org> # 4.2+

Arnd, would you be still able to pick it up in this cycle?

Thanks Both!

Pawe?

[PATCH] bus: arm-ccn: Fix cpu notifier priority

[Jan Glauber]

On Wed, Mar 09, 2016 at 08:40:45AM +0000, Pawel Moll wrote:
> On Tue, 2016-03-08 at 13:14 +0100, Jan Glauber wrote:
> > Fix cpu priority of notifier block that was erroneously set to
> > return value of next statement.
> > 
> > Signed-off-by: Jan Glauber <jglauber@cavium.com>
> > ---
> >  drivers/bus/arm-ccn.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
> > index 7082c72..d4a939e 100644
> > --- a/drivers/bus/arm-ccn.c
> > +++ b/drivers/bus/arm-ccn.c
> > @@ -1271,7 +1271,7 @@ static int arm_ccn_pmu_init(struct arm_ccn
> > *ccn)
> >  	 * picked to have a chance to migrate events before perf is
> > notified.
> >  	 */
> >  	ccn->dt.cpu_nb.notifier_call = arm_ccn_pmu_cpu_notifier;
> > -	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1,
> > +	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1;
> >  	err = register_cpu_notifier(&ccn->dt.cpu_nb);
> >  	if (err)
> >  		goto error_cpu_notifier;
> 
> Damn, of course! I have never made (or heard about) such a typo before 
> - I wish the compiler warned about it :-(

Yeah, I was also surprised that we have plenty of cosmetical checks
but nothing that catches this bug.

Maybe it's not too hard to catch the simple case, just check for a line
with assignment and no brackets / parenthesis ended by a comma?

Jan

> By all means:
> 
> Acked-by: Pawel Moll <pawel.moll@arm.com>
> Cc: <stable@vger.kernel.org> # 4.2+
> 
> Arnd, would you be still able to pick it up in this cycle?
> 
> Thanks Both!
> 
> Pawe?

[PATCH] bus: arm-ccn: Fix cpu notifier priority

[Jan Glauber]

On Wed, Mar 09, 2016 at 08:40:45AM +0000, Pawel Moll wrote:
> On Tue, 2016-03-08 at 13:14 +0100, Jan Glauber wrote:
> > Fix cpu priority of notifier block that was erroneously set to
> > return value of next statement.
> > 
> > Signed-off-by: Jan Glauber <jglauber@cavium.com>
> > ---
> >  drivers/bus/arm-ccn.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
> > index 7082c72..d4a939e 100644
> > --- a/drivers/bus/arm-ccn.c
> > +++ b/drivers/bus/arm-ccn.c
> > @@ -1271,7 +1271,7 @@ static int arm_ccn_pmu_init(struct arm_ccn
> > *ccn)
> >  	 * picked to have a chance to migrate events before perf is
> > notified.
> >  	 */
> >  	ccn->dt.cpu_nb.notifier_call = arm_ccn_pmu_cpu_notifier;
> > -	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1,
> > +	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1;
> >  	err = register_cpu_notifier(&ccn->dt.cpu_nb);
> >  	if (err)
> >  		goto error_cpu_notifier;
> 
> Damn, of course! I have never made (or heard about) such a typo before 
> - I wish the compiler warned about it :-(

Hi Pawel,

actually my patch description is wrong. The compiler evaluates both
statements but does _not_ overwrite the value of the first statement
(would require parenthesis to do so). So it is just a cosmetical
change, feel free to drop it.

Sorry for the noise,
Jan

> By all means:
> 
> Acked-by: Pawel Moll <pawel.moll@arm.com>
> Cc: <stable@vger.kernel.org> # 4.2+
> 
> Arnd, would you be still able to pick it up in this cycle?
> 
> Thanks Both!
> 
> Pawe?

[PATCH] bus: arm-ccn: Fix cpu notifier priority

[Pawel Moll]

On Thu, 2016-03-10 at 15:34 +0100, Jan Glauber wrote:
> On Wed, Mar 09, 2016 at 08:40:45AM +0000, Pawel Moll wrote:
> > On Tue, 2016-03-08 at 13:14 +0100, Jan Glauber wrote:
> > > Fix cpu priority of notifier block that was erroneously set to
> > > return value of next statement.
> > > 
> > > Signed-off-by: Jan Glauber <jglauber@cavium.com>
> > > ---
> > >  drivers/bus/arm-ccn.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
> > > index 7082c72..d4a939e 100644
> > > --- a/drivers/bus/arm-ccn.c
> > > +++ b/drivers/bus/arm-ccn.c
> > > @@ -1271,7 +1271,7 @@ static int arm_ccn_pmu_init(struct arm_ccn
> > > *ccn)
> > >  	 * picked to have a chance to migrate events before perf
> > > is
> > > notified.
> > >  	 */
> > >  	ccn->dt.cpu_nb.notifier_call = arm_ccn_pmu_cpu_notifier;
> > > -	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1,
> > > +	ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1;
> > >  	err = register_cpu_notifier(&ccn->dt.cpu_nb);
> > >  	if (err)
> > >  		goto error_cpu_notifier;
> > 
> > Damn, of course! I have never made (or heard about) such a typo
> > before 
> > - I wish the compiler warned about it :-(
> 
> actually my patch description is wrong. The compiler evaluates both
> statements but does _not_ overwrite the value of the first statement
> (would require parenthesis to do so).

I must admit I looked at the code change rather than at the
description, but thinking about it now, comma has the lowest
precedence, so the assignments will win. Still, with gcc 6 now warning
about suspicious indentations, my wish still stays a wish ;-)

>  So it is just a cosmetical change, feel free to drop it.

Oh no, it's still a bug (only maybe not a "stable-class" one). And one
I'll remember :-) 

Thanks!

Pawel