[PATCH] perf: arm-ni: Fix attribute_group definition syntax

[PATCH] perf: arm-ni: Fix attribute_group definition syntax

[Thomas Weißschuh]

The sentinel NULL value does not make sense and is a syntax error in a
structure definition.
Remove it.

Fixes: 4d5a7680f2b4 ("perf: Add driver for Arm NI-700 interconnect PMU")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
Cc stable because although this commit is not yet released, it most
likely will be by the time it hits mainline.
---
 drivers/perf/arm-ni.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/perf/arm-ni.c b/drivers/perf/arm-ni.c
index 90fcfe693439ef3e18e23c6351433ac3c5ea78b5..fd7a5e60e96302fada29cd44e7bf9c582e93e4ce 100644
--- a/drivers/perf/arm-ni.c
+++ b/drivers/perf/arm-ni.c
@@ -247,7 +247,6 @@ static struct attribute *arm_ni_other_attrs[] = {
 
 static const struct attribute_group arm_ni_other_attr_group = {
 	.attrs = arm_ni_other_attrs,
-	NULL
 };
 
 static const struct attribute_group *arm_ni_attr_groups[] = {

---
base-commit: 4a5df37964673effcd9f84041f7423206a5ae5f2
change-id: 20241117-arm-ni-syntax-250a83058529

Best regards,
-- 
Thomas Weißschuh <linux@weissschuh.net>

Re: [PATCH] perf: arm-ni: Fix attribute_group definition syntax

[Robin Murphy]

On 2024-11-17 10:20 am, Thomas Weißschuh wrote:
> The sentinel NULL value does not make sense and is a syntax error in a
> structure definition.

What error? It's an initialiser following a designator in a structure 
*declaration*, and the corresponding bin_attrs member is a pointer, so 
NULL is a perfectly appropriate value to initialise it with.

Of course that is redundant when it's static anyway, and indeed wasn't 
actually intentional, but it's also not doing any harm - the cosmetic 
cleanup is welcome, but is not a stable-worthy fix.

Thanks,
Robin.

> Remove it.
> 
> Fixes: 4d5a7680f2b4 ("perf: Add driver for Arm NI-700 interconnect PMU")
> Cc: stable@vger.kernel.org
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---
> Cc stable because although this commit is not yet released, it most
> likely will be by the time it hits mainline.
> ---
>   drivers/perf/arm-ni.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/perf/arm-ni.c b/drivers/perf/arm-ni.c
> index 90fcfe693439ef3e18e23c6351433ac3c5ea78b5..fd7a5e60e96302fada29cd44e7bf9c582e93e4ce 100644
> --- a/drivers/perf/arm-ni.c
> +++ b/drivers/perf/arm-ni.c
> @@ -247,7 +247,6 @@ static struct attribute *arm_ni_other_attrs[] = {
>   
>   static const struct attribute_group arm_ni_other_attr_group = {
>   	.attrs = arm_ni_other_attrs,
> -	NULL
>   };
>   
>   static const struct attribute_group *arm_ni_attr_groups[] = {
> 
> ---
> base-commit: 4a5df37964673effcd9f84041f7423206a5ae5f2
> change-id: 20241117-arm-ni-syntax-250a83058529
> 
> Best regards,

Re: [PATCH] perf: arm-ni: Fix attribute_group definition syntax

[Thomas Weißschuh]

On 2024-11-18 11:55:17+0000, Robin Murphy wrote:
> On 2024-11-17 10:20 am, Thomas Weißschuh wrote:
> > The sentinel NULL value does not make sense and is a syntax error in a
> > structure definition.
> 
> What error? It's an initialiser following a designator in a structure
> *declaration*, and the corresponding bin_attrs member is a pointer, so NULL
> is a perfectly appropriate value to initialise it with.

Yes, you are correct. The warning only occurs in my series which changes
bin_attrs to a union [0] and I got confused due to some missing and
inconsisteny build bot feedback.

> Of course that is redundant when it's static anyway, and indeed wasn't
> actually intentional, but it's also not doing any harm - the cosmetic
> cleanup is welcome, but is not a stable-worthy fix.

Agreed, it's not worthy for stable.
Actually I want to make this patch part of a series, so please ignore
it for now.

> Thanks,
> Robin.

[0] https://lore.kernel.org/lkml/20241115-b4-sysfs-const-bin_attr-group-v1-1-2c9bb12dfc48@weissschuh.net/

> > Remove it.
> > 
> > Fixes: 4d5a7680f2b4 ("perf: Add driver for Arm NI-700 interconnect PMU")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> > ---
> > Cc stable because although this commit is not yet released, it most
> > likely will be by the time it hits mainline.
> > ---
> >   drivers/perf/arm-ni.c | 1 -
> >   1 file changed, 1 deletion(-)
> > 
> > diff --git a/drivers/perf/arm-ni.c b/drivers/perf/arm-ni.c
> > index 90fcfe693439ef3e18e23c6351433ac3c5ea78b5..fd7a5e60e96302fada29cd44e7bf9c582e93e4ce 100644
> > --- a/drivers/perf/arm-ni.c
> > +++ b/drivers/perf/arm-ni.c
> > @@ -247,7 +247,6 @@ static struct attribute *arm_ni_other_attrs[] = {
> >   static const struct attribute_group arm_ni_other_attr_group = {
> >   	.attrs = arm_ni_other_attrs,
> > -	NULL
> >   };
> >   static const struct attribute_group *arm_ni_attr_groups[] = {
> > 
> > ---
> > base-commit: 4a5df37964673effcd9f84041f7423206a5ae5f2
> > change-id: 20241117-arm-ni-syntax-250a83058529
> > 
> > Best regards,
>