[PATCH v3] staging: greybus: Constify static struct kobj_type gb_audio_module_type

[PATCH v3] staging: greybus: Constify static struct kobj_type gb_audio_module_type

[Ayush Tiwari]

Constify static struct kobj_type gb_audio_module_type to prevent
modification of data shared across many instances, ensuring that the
structure's usage is consistent and predictable throughout the driver
and allows the compiler to place it in read-only memory.
The kernel builds successfully without errors or new warnings,
verifying the change.

Signed-off-by: Ayush Tiwari <ayushtiw0110@gmail.com>
---
Changes in v3: added the message that verifies the change,
as suggested by Julia

Changes in v2: incorporated changes in commit message
as suggested by Alison
---
 drivers/staging/greybus/audio_manager_module.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/greybus/audio_manager_module.c b/drivers/staging/greybus/audio_manager_module.c
index 5f9dcbdbc191..4a4dfb42f50f 100644
--- a/drivers/staging/greybus/audio_manager_module.c
+++ b/drivers/staging/greybus/audio_manager_module.c
@@ -144,7 +144,7 @@ static struct attribute *gb_audio_module_default_attrs[] = {
 };
 ATTRIBUTE_GROUPS(gb_audio_module_default);
 
-static struct kobj_type gb_audio_module_type = {
+static const struct kobj_type gb_audio_module_type = {
 	.sysfs_ops = &gb_audio_module_sysfs_ops,
 	.release = gb_audio_module_release,
 	.default_groups = gb_audio_module_default_groups,
-- 
2.40.1

Re: [PATCH v3] staging: greybus: Constify static struct kobj_type gb_audio_module_type

[Julia Lawall]

On Thu, 14 Mar 2024, Ayush Tiwari wrote:

> Constify static struct kobj_type gb_audio_module_type to prevent
> modification of data shared across many instances, ensuring that the
> structure's usage is consistent and predictable throughout the driver
> and allows the compiler to place it in read-only memory.
> The kernel builds successfully without errors or new warnings,
> verifying the change.

Actually, casts can hide issues with const, so building successfully is
not a sufficient answer.  Where is this structure used, and how?

julia

>
> Signed-off-by: Ayush Tiwari <ayushtiw0110@gmail.com>
> ---
> Changes in v3: added the message that verifies the change,
> as suggested by Julia
>
> Changes in v2: incorporated changes in commit message
> as suggested by Alison
> ---
>  drivers/staging/greybus/audio_manager_module.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/greybus/audio_manager_module.c b/drivers/staging/greybus/audio_manager_module.c
> index 5f9dcbdbc191..4a4dfb42f50f 100644
> --- a/drivers/staging/greybus/audio_manager_module.c
> +++ b/drivers/staging/greybus/audio_manager_module.c
> @@ -144,7 +144,7 @@ static struct attribute *gb_audio_module_default_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(gb_audio_module_default);
>
> -static struct kobj_type gb_audio_module_type = {
> +static const struct kobj_type gb_audio_module_type = {
>  	.sysfs_ops = &gb_audio_module_sysfs_ops,
>  	.release = gb_audio_module_release,
>  	.default_groups = gb_audio_module_default_groups,
> --
> 2.40.1
>
>
>

Re: [PATCH v3] staging: greybus: Constify static struct kobj_type gb_audio_module_type

[Fabio M. De Francesco]

On Thursday, 14 March 2024 09:13:22 CET Ayush Tiwari wrote:
> Constify static struct kobj_type gb_audio_module_type to prevent
> modification of data shared across many instances, ensuring that the
> structure's usage is consistent and predictable throughout the driver
> and allows the compiler to place it in read-only memory.
> The kernel builds successfully without errors or new warnings,
> verifying the change.
> 
> Signed-off-by: Ayush Tiwari <ayushtiw0110@gmail.com>
> ---

I think that the "Subject" line should be made shorter by deleting all the 
unnecessary information. I'm not asking you to make a new version just to 
address my comment, but please keep the following in mind for your next 
patches.

The "Subject" line is provided (1) to briefly explain what this patch is 
doing and (2) to uniquely identify the patch (e.g., in git-log output).

I'd write something like the following:

"staging: greybus: Constify gb_audio_module_type"

Who reads the subject doesn't need, and probably doesn't want, to know that 
the variable you are making "const" has a "static" modifier or that its type 
is "struct kobj_type". These information add nothing relevant to what the 
patch is doing.

Examples of shorter, yet sufficient, "Subject" lines:

7ab4de60028e virtio-mem: Constify mem_id_table
01e1932a1748 iommu/vt-d: Constify intel_dma_ops

Thanks,

Fabio

> Changes in v3: added the message that verifies the change,
> as suggested by Julia
> 
> Changes in v2: incorporated changes in commit message
> as suggested by Alison
> ---

>  drivers/staging/greybus/audio_manager_module.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/greybus/audio_manager_module.c
> b/drivers/staging/greybus/audio_manager_module.c index
> 5f9dcbdbc191..4a4dfb42f50f 100644
> --- a/drivers/staging/greybus/audio_manager_module.c
> +++ b/drivers/staging/greybus/audio_manager_module.c
> @@ -144,7 +144,7 @@ static struct attribute 
*gb_audio_module_default_attrs[]
> = { };
>  ATTRIBUTE_GROUPS(gb_audio_module_default);
> 
> -static struct kobj_type gb_audio_module_type = {
> +static const struct kobj_type gb_audio_module_type = {
>  	.sysfs_ops = &gb_audio_module_sysfs_ops,
>  	.release = gb_audio_module_release,
>  	.default_groups = gb_audio_module_default_groups,