[PATCH] iio: chemical: scd30: make command lookup table const

[PATCH] iio: chemical: scd30: make command lookup table const

[Giorgi Tchankvetadze]

scd30_i2c_cmd_lookup_tbl contains fixed opcodes and is
only read by scd30_i2c_command(). Make it const to document that it's immutable
and allow it to be placed in read-only memory.

Signed-off-by: Giorgi Tchankvetadze <giorgitchankvetadze1997@gmail.com>
---
 drivers/iio/chemical/scd30_i2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/chemical/scd30_i2c.c b/drivers/iio/chemical/scd30_i2c.c
index 436df9c61a71..bf465cc71be7 100644
--- a/drivers/iio/chemical/scd30_i2c.c
+++ b/drivers/iio/chemical/scd30_i2c.c
@@ -20,7 +20,7 @@
 #define SCD30_I2C_MAX_BUF_SIZE 18
 #define SCD30_I2C_CRC8_POLYNOMIAL 0x31
 
-static u16 scd30_i2c_cmd_lookup_tbl[] = {
+static const u16 scd30_i2c_cmd_lookup_tbl[] = {
 	[CMD_START_MEAS] = 0x0010,
 	[CMD_STOP_MEAS] = 0x0104,
 	[CMD_MEAS_INTERVAL] = 0x4600,
-- 
2.52.0

Re: [PATCH] iio: chemical: scd30: make command lookup table const

[Maxwell Doose]

On Fri, May 8, 2026 at 8:53 AM Giorgi Tchankvetadze
<giorgitchankvetadze1997@gmail.com> wrote:
>
> scd30_i2c_cmd_lookup_tbl contains fixed opcodes and is
> only read by scd30_i2c_command(). Make it const to document that it's immutable
> and allow it to be placed in read-only memory.
>
> Signed-off-by: Giorgi Tchankvetadze <giorgitchankvetadze1997@gmail.com>
> ---
>  drivers/iio/chemical/scd30_i2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
[snip]

Looks fine to me.

Acked-by: Maxwell Doose <m32285159@gmail.com>

best regards,
max

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Stepan Ionichev]

scd30_i2c_cmd_lookup_tbl[] holds the fixed CMD_* opcodes and is only
ever read in scd30_i2c_command() (via put_unaligned_be16 of the looked
up entry). Marking it const matches how it is used and lets the table
land in .rodata.

Reviewed-by: Stepan Ionichev <sozdayvek@gmail.com>

Stepan

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Stepan Ionichev]

On Sun, 10 May 2026, Andy Shevchenko wrote:
> > scd30_i2c_cmd_lookup_tbl[] holds the fixed CMD_* opcodes and is only
> > ever read in scd30_i2c_command() (via put_unaligned_be16 of the looked
> > up entry). Marking it const matches how it is used and lets the table
> > land in .rodata.
>
> I believe the above is the suggestion on the correction of the commit message?
> Please, make it clear!

Sorry for the ambiguity -- that paragraph was just my own reasoning
for the Reviewed-by tag (i.e. what I checked and why I think the
change is correct), not a proposed rewording of the commit message.
Giorgi's commit message already reads fine; no changes requested
from me.

Stepan

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Stepan Ionichev]

On Sun, 10 May 2026, Maxwell Doose wrote:
> I'm curious, are you having AI do your reviews?

English is not my native language, so I use AI to help with phrasing
and to learn kernel review style. The technical analysis I do myself
-- for this patch I checked via grep that scd30_i2c_cmd_lookup_tbl[]
is only read (one read site in scd30_i2c_command() via
put_unaligned_be16, no writes), which is what supports the const
change being correct.

Happy to follow whatever disclosure norm the iio community prefers.

Stepan

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Stepan Ionichev]

Thanks, makes sense. I'll stick with just the R-b tag for the next ones.

Stepan

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Andy Shevchenko]

On Sat, May 09, 2026 at 04:16:33PM +0500, Stepan Ionichev wrote:
> scd30_i2c_cmd_lookup_tbl[] holds the fixed CMD_* opcodes and is only
> ever read in scd30_i2c_command() (via put_unaligned_be16 of the looked
> up entry). Marking it const matches how it is used and lets the table
> land in .rodata.

I believe the above is the suggestion on the correction of the commit message?
Please, make it clear!

> Reviewed-by: Stepan Ionichev <sozdayvek@gmail.com>

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Maxwell Doose]

On Sun, May 10, 2026 at 2:47 AM Stepan Ionichev <sozdayvek@gmail.com> wrote:
>
> On Sun, 10 May 2026, Andy Shevchenko wrote:
> > > scd30_i2c_cmd_lookup_tbl[] holds the fixed CMD_* opcodes and is only
> > > ever read in scd30_i2c_command() (via put_unaligned_be16 of the looked
> > > up entry). Marking it const matches how it is used and lets the table
> > > land in .rodata.
> >
> > I believe the above is the suggestion on the correction of the commit message?
> > Please, make it clear!
>
> Sorry for the ambiguity -- that paragraph was just my own reasoning
> for the Reviewed-by tag (i.e. what I checked and why I think the
> change is correct), not a proposed rewording of the commit message.
> Giorgi's commit message already reads fine; no changes requested
> from me.
>

I'm curious, are you having AI do your reviews?

best regards,
max

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Maxwell Doose]

On Sun, May 10, 2026 at 2:59 AM Stepan Ionichev <sozdayvek@gmail.com> wrote:
>
> On Sun, 10 May 2026, Maxwell Doose wrote:
> > I'm curious, are you having AI do your reviews?
>
> English is not my native language, so I use AI to help with phrasing
> and to learn kernel review style. The technical analysis I do myself
> -- for this patch I checked via grep that scd30_i2c_cmd_lookup_tbl[]
> is only read (one read site in scd30_i2c_command() via
> put_unaligned_be16, no writes), which is what supports the const
> change being correct.
>

Thanks for confirming, just wanted to check since some of the phrasing
in your review did seem very AI-like.

>
> Happy to follow whatever disclosure norm the iio community prefers.
>

Typically reviews end up being one-liners (e.g., Reviewed-by: name
<email>) and that ends up being the whole message, sometimes reviewers
and maintainers will have inline comments. Obviously you don't have to
follow those norms but that's just what usually ends up happening.

best regards,
max

> Stepan

Re: [PATCH 3/3] iio: chemical: scd30: make command lookup table const

[Andy Shevchenko]

On Sun, May 10, 2026 at 03:04:28AM -0500, Maxwell Doose wrote:
> On Sun, May 10, 2026 at 2:59 AM Stepan Ionichev <sozdayvek@gmail.com> wrote:
> > On Sun, 10 May 2026, Maxwell Doose wrote:
> > > I'm curious, are you having AI do your reviews?
> >
> > English is not my native language, so I use AI to help with phrasing
> > and to learn kernel review style. The technical analysis I do myself
> > -- for this patch I checked via grep that scd30_i2c_cmd_lookup_tbl[]
> > is only read (one read site in scd30_i2c_command() via
> > put_unaligned_be16, no writes), which is what supports the const
> > change being correct.
> 
> Thanks for confirming, just wanted to check since some of the phrasing
> in your review did seem very AI-like.
> 
> > Happy to follow whatever disclosure norm the iio community prefers.
> 
> Typically reviews end up being one-liners (e.g., Reviewed-by: name
> <email>) and that ends up being the whole message, sometimes reviewers
> and maintainers will have inline comments. Obviously you don't have to
> follow those norms but that's just what usually ends up happening.

The good review includes reasoning, and Stepan's is a good one, just needed
clarification, because I haven't got if it's a proposal to have a commit
message changed or summary of the review.

> > Stepan

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] iio: chemical: scd30: make command lookup table const

[Jonathan Cameron]

On Fri,  8 May 2026 17:39:17 +0400
Giorgi Tchankvetadze <giorgitchankvetadze1997@gmail.com> wrote:

> scd30_i2c_cmd_lookup_tbl contains fixed opcodes and is
> only read by scd30_i2c_command(). Make it const to document that it's immutable
> and allow it to be placed in read-only memory.
> 
> Signed-off-by: Giorgi Tchankvetadze <giorgitchankvetadze1997@gmail.com>
Applied to the testing branch of iio.git.  Thanks,

Jonathan

> ---
>  drivers/iio/chemical/scd30_i2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/chemical/scd30_i2c.c b/drivers/iio/chemical/scd30_i2c.c
> index 436df9c61a71..bf465cc71be7 100644
> --- a/drivers/iio/chemical/scd30_i2c.c
> +++ b/drivers/iio/chemical/scd30_i2c.c
> @@ -20,7 +20,7 @@
>  #define SCD30_I2C_MAX_BUF_SIZE 18
>  #define SCD30_I2C_CRC8_POLYNOMIAL 0x31
>  
> -static u16 scd30_i2c_cmd_lookup_tbl[] = {
> +static const u16 scd30_i2c_cmd_lookup_tbl[] = {
>  	[CMD_START_MEAS] = 0x0010,
>  	[CMD_STOP_MEAS] = 0x0104,
>  	[CMD_MEAS_INTERVAL] = 0x4600,