Re: [PATCH] ath9k: Add cast to u8 to FREQ2FBIN macro

[Joe Perches]

On Thu, 2017-04-06 at 16:54 -0700, Matthias Kaehlcke wrote:
> Hi Joe,
> 
> El Thu, Apr 06, 2017 at 02:29:20PM -0700 Joe Perches ha dit:
> 
> > On Thu, 2017-04-06 at 14:21 -0700, Matthias Kaehlcke wrote:
> > > The macro results are assigned to u8 variables/fields. Adding the cast
> > > fixes plenty of clang warnings about "implicit conversion from 'int' to
> > > 'u8'".
> > > 
> > > Signed-off-by: Matthias Kaehlcke 
> > > ---
> > >  drivers/net/wireless/ath/ath9k/eeprom.h | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h 
> > > b/drivers/net/wireless/ath/ath9k/eeprom.h
> > > index 30bf722e33ed..31390af6c33e 100644
> > > --- a/drivers/net/wireless/ath/ath9k/eeprom.h
> > > +++ b/drivers/net/wireless/ath/ath9k/eeprom.h
> > > @@ -106,7 +106,7 @@
> > >  #define AR9285_RDEXT_DEFAULT0x1F
> > >  
> > >  #define ATH9K_POW_SM(_r, _s) (((_r) & 0x3f) << (_s))
> > > -#define FREQ2FBIN(x, y)  ((y) ? ((x) - 2300) : (((x) - 4800) / 
> > > 5))
> > > +#define FREQ2FBIN(x, y)  (u8)((y) ? ((x) - 2300) : (((x) - 4800) 
> > > / 5))
> > 
> > Maybe better to use:
> > 
> > static inline u8 FREQ2FBIN(int x, int y)
> > {
> > if (y)
> > return x - 2300;
> > return (x - 4800) / 5;
> > }
> 
> Thanks for your suggestion! Unfortunately in this case an inline
> function is not suitable since FREQ2FBIN() is mostly used for
> structure initialization:
> 
> static const struct ar9300_eeprom ar9300_default = {
> ...
> .calFreqPier2G = {
> FREQ2FBIN(2412, 1),
> FREQ2FBIN(2437, 1),
> FREQ2FBIN(2472, 1)
> },
> ...

Maybe it's better to remove the second argument and write
something like:

#define FREQ2FBIN(x) \
(u8)(((x) >= 2300 && (x) <= 2555) ? (x) - 2300 : \
 ((x) >= 4800 && (x) <= 4800 + (256 * 5) ? ((x) - 4800) / 5) : \
 __builtin_const_p(x) ? BUILD_BUG_ON(1) : 0)

Re: [PATCH] ath9k: Add cast to u8 to FREQ2FBIN macro

[Joe Perches]

On Thu, 2017-04-06 at 16:54 -0700, Matthias Kaehlcke wrote:
> Hi Joe,
> 
> El Thu, Apr 06, 2017 at 02:29:20PM -0700 Joe Perches ha dit:
> 
> > On Thu, 2017-04-06 at 14:21 -0700, Matthias Kaehlcke wrote:
> > > The macro results are assigned to u8 variables/fields. Adding the cast
> > > fixes plenty of clang warnings about "implicit conversion from 'int' to
> > > 'u8'".
> > > 
> > > Signed-off-by: Matthias Kaehlcke 
> > > ---
> > >  drivers/net/wireless/ath/ath9k/eeprom.h | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h 
> > > b/drivers/net/wireless/ath/ath9k/eeprom.h
> > > index 30bf722e33ed..31390af6c33e 100644
> > > --- a/drivers/net/wireless/ath/ath9k/eeprom.h
> > > +++ b/drivers/net/wireless/ath/ath9k/eeprom.h
> > > @@ -106,7 +106,7 @@
> > >  #define AR9285_RDEXT_DEFAULT0x1F
> > >  
> > >  #define ATH9K_POW_SM(_r, _s) (((_r) & 0x3f) << (_s))
> > > -#define FREQ2FBIN(x, y)  ((y) ? ((x) - 2300) : (((x) - 4800) / 
> > > 5))
> > > +#define FREQ2FBIN(x, y)  (u8)((y) ? ((x) - 2300) : (((x) - 4800) 
> > > / 5))
> > 
> > Maybe better to use:
> > 
> > static inline u8 FREQ2FBIN(int x, int y)
> > {
> > if (y)
> > return x - 2300;
> > return (x - 4800) / 5;
> > }
> 
> Thanks for your suggestion! Unfortunately in this case an inline
> function is not suitable since FREQ2FBIN() is mostly used for
> structure initialization:
> 
> static const struct ar9300_eeprom ar9300_default = {
> ...
> .calFreqPier2G = {
> FREQ2FBIN(2412, 1),
> FREQ2FBIN(2437, 1),
> FREQ2FBIN(2472, 1)
> },
> ...

Maybe it's better to remove the second argument and write
something like:

#define FREQ2FBIN(x) \
(u8)(((x) >= 2300 && (x) <= 2555) ? (x) - 2300 : \
 ((x) >= 4800 && (x) <= 4800 + (256 * 5) ? ((x) - 4800) / 5) : \
 __builtin_const_p(x) ? BUILD_BUG_ON(1) : 0)

Re: [PATCH] ath9k: Add cast to u8 to FREQ2FBIN macro

[Matthias Kaehlcke]

Hi Joe,

El Thu, Apr 06, 2017 at 02:29:20PM -0700 Joe Perches ha dit:

> On Thu, 2017-04-06 at 14:21 -0700, Matthias Kaehlcke wrote:
> > The macro results are assigned to u8 variables/fields. Adding the cast
> > fixes plenty of clang warnings about "implicit conversion from 'int' to
> > 'u8'".
> > 
> > Signed-off-by: Matthias Kaehlcke 
> > ---
> >  drivers/net/wireless/ath/ath9k/eeprom.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h 
> > b/drivers/net/wireless/ath/ath9k/eeprom.h
> > index 30bf722e33ed..31390af6c33e 100644
> > --- a/drivers/net/wireless/ath/ath9k/eeprom.h
> > +++ b/drivers/net/wireless/ath/ath9k/eeprom.h
> > @@ -106,7 +106,7 @@
> >  #define AR9285_RDEXT_DEFAULT0x1F
> >  
> >  #define ATH9K_POW_SM(_r, _s)   (((_r) & 0x3f) << (_s))
> > -#define FREQ2FBIN(x, y)((y) ? ((x) - 2300) : (((x) - 4800) / 
> > 5))
> > +#define FREQ2FBIN(x, y)(u8)((y) ? ((x) - 2300) : (((x) - 4800) 
> > / 5))
> 
> Maybe better to use:
> 
> static inline u8 FREQ2FBIN(int x, int y)
> {
>   if (y)
>   return x - 2300;
>   return (x - 4800) / 5;
> }

Thanks for your suggestion! Unfortunately in this case an inline
function is not suitable since FREQ2FBIN() is mostly used for
structure initialization:

static const struct ar9300_eeprom ar9300_default = {
...
.calFreqPier2G = {
FREQ2FBIN(2412, 1),
FREQ2FBIN(2437, 1),
FREQ2FBIN(2472, 1),
},
...

Cheers

Matthias

Re: [PATCH] ath9k: Add cast to u8 to FREQ2FBIN macro

[Matthias Kaehlcke]

Hi Joe,

El Thu, Apr 06, 2017 at 02:29:20PM -0700 Joe Perches ha dit:

> On Thu, 2017-04-06 at 14:21 -0700, Matthias Kaehlcke wrote:
> > The macro results are assigned to u8 variables/fields. Adding the cast
> > fixes plenty of clang warnings about "implicit conversion from 'int' to
> > 'u8'".
> > 
> > Signed-off-by: Matthias Kaehlcke 
> > ---
> >  drivers/net/wireless/ath/ath9k/eeprom.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h 
> > b/drivers/net/wireless/ath/ath9k/eeprom.h
> > index 30bf722e33ed..31390af6c33e 100644
> > --- a/drivers/net/wireless/ath/ath9k/eeprom.h
> > +++ b/drivers/net/wireless/ath/ath9k/eeprom.h
> > @@ -106,7 +106,7 @@
> >  #define AR9285_RDEXT_DEFAULT0x1F
> >  
> >  #define ATH9K_POW_SM(_r, _s)   (((_r) & 0x3f) << (_s))
> > -#define FREQ2FBIN(x, y)((y) ? ((x) - 2300) : (((x) - 4800) / 
> > 5))
> > +#define FREQ2FBIN(x, y)(u8)((y) ? ((x) - 2300) : (((x) - 4800) 
> > / 5))
> 
> Maybe better to use:
> 
> static inline u8 FREQ2FBIN(int x, int y)
> {
>   if (y)
>   return x - 2300;
>   return (x - 4800) / 5;
> }

Thanks for your suggestion! Unfortunately in this case an inline
function is not suitable since FREQ2FBIN() is mostly used for
structure initialization:

static const struct ar9300_eeprom ar9300_default = {
...
.calFreqPier2G = {
FREQ2FBIN(2412, 1),
FREQ2FBIN(2437, 1),
FREQ2FBIN(2472, 1),
},
...

Cheers

Matthias

Re: [PATCH] ath9k: Add cast to u8 to FREQ2FBIN macro

[Joe Perches]

On Thu, 2017-04-06 at 14:21 -0700, Matthias Kaehlcke wrote:
> The macro results are assigned to u8 variables/fields. Adding the cast
> fixes plenty of clang warnings about "implicit conversion from 'int' to
> 'u8'".
> 
> Signed-off-by: Matthias Kaehlcke 
> ---
>  drivers/net/wireless/ath/ath9k/eeprom.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h 
> b/drivers/net/wireless/ath/ath9k/eeprom.h
> index 30bf722e33ed..31390af6c33e 100644
> --- a/drivers/net/wireless/ath/ath9k/eeprom.h
> +++ b/drivers/net/wireless/ath/ath9k/eeprom.h
> @@ -106,7 +106,7 @@
>  #define AR9285_RDEXT_DEFAULT0x1F
>  
>  #define ATH9K_POW_SM(_r, _s) (((_r) & 0x3f) << (_s))
> -#define FREQ2FBIN(x, y)  ((y) ? ((x) - 2300) : (((x) - 4800) / 
> 5))
> +#define FREQ2FBIN(x, y)  (u8)((y) ? ((x) - 2300) : (((x) - 4800) 
> / 5))

Maybe better to use:

static inline u8 FREQ2FBIN(int x, int y)
{
if (y)
return x - 2300;
return (x - 4800) / 5;
}

Re: [PATCH] ath9k: Add cast to u8 to FREQ2FBIN macro

[Joe Perches]

On Thu, 2017-04-06 at 14:21 -0700, Matthias Kaehlcke wrote:
> The macro results are assigned to u8 variables/fields. Adding the cast
> fixes plenty of clang warnings about "implicit conversion from 'int' to
> 'u8'".
> 
> Signed-off-by: Matthias Kaehlcke 
> ---
>  drivers/net/wireless/ath/ath9k/eeprom.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h 
> b/drivers/net/wireless/ath/ath9k/eeprom.h
> index 30bf722e33ed..31390af6c33e 100644
> --- a/drivers/net/wireless/ath/ath9k/eeprom.h
> +++ b/drivers/net/wireless/ath/ath9k/eeprom.h
> @@ -106,7 +106,7 @@
>  #define AR9285_RDEXT_DEFAULT0x1F
>  
>  #define ATH9K_POW_SM(_r, _s) (((_r) & 0x3f) << (_s))
> -#define FREQ2FBIN(x, y)  ((y) ? ((x) - 2300) : (((x) - 4800) / 
> 5))
> +#define FREQ2FBIN(x, y)  (u8)((y) ? ((x) - 2300) : (((x) - 4800) 
> / 5))

Maybe better to use:

static inline u8 FREQ2FBIN(int x, int y)
{
if (y)
return x - 2300;
return (x - 4800) / 5;
}