Re: [PATCH 2/3] i2c: mux: pca9541: namespace cleanup

From: Vladimir Zapolskiy
Date: Wed Mar 21 2018 - 02:54:15 EST


Hi Peter,

On 03/21/2018 07:53 AM, Peter Rosin wrote:
> On 2018-03-21 00:24, Vladimir Zapolskiy wrote:
>> Hi Peter,
>>
>> On 03/20/2018 11:31 AM, Peter Rosin wrote:
>>> In preparation for PCA9641 support, convert the mybus and busoff macros
>>> to functions, and in the process prefix them with pca9541_. Also prefix
>>> remaining chip specific macros with PCA9541_.
>>>
>>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
>>> ---
>>> drivers/i2c/muxes/i2c-mux-pca9541.c | 26 +++++++++++++++++++-------
>>> 1 file changed, 19 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/i2c/muxes/i2c-mux-pca9541.c b/drivers/i2c/muxes/i2c-mux-pca9541.c
>>> index ad168125d23d..47685eb4e0e9 100644
>>> --- a/drivers/i2c/muxes/i2c-mux-pca9541.c
>>> +++ b/drivers/i2c/muxes/i2c-mux-pca9541.c
>>> @@ -59,10 +59,8 @@
>>> #define PCA9541_ISTAT_MYTEST BIT(6)
>>> #define PCA9541_ISTAT_NMYTEST BIT(7)
>>>
>>> -#define BUSON (PCA9541_CTL_BUSON | PCA9541_CTL_NBUSON)
>>> -#define MYBUS (PCA9541_CTL_MYBUS | PCA9541_CTL_NMYBUS)
>>> -#define mybus(x) (!((x) & MYBUS) || ((x) & MYBUS) == MYBUS)
>>> -#define busoff(x) (!((x) & BUSON) || ((x) & BUSON) == BUSON)
>>> +#define PCA9541_BUSON (PCA9541_CTL_BUSON | PCA9541_CTL_NBUSON)
>>> +#define PCA9541_MYBUS (PCA9541_CTL_MYBUS | PCA9541_CTL_NMYBUS)
>>>
>>> /* arbitration timeouts, in jiffies */
>>> #define ARB_TIMEOUT (HZ / 8) /* 125 ms until forcing bus ownership */
>>> @@ -93,6 +91,20 @@ static const struct of_device_id pca9541_of_match[] = {
>>> MODULE_DEVICE_TABLE(of, pca9541_of_match);
>>> #endif
>>>
>>> +static int pca9541_mybus(int ctl)
>>
>> static inline?
>
> No, "inline" is only used in header files in the kernel.

No, it is an incorrect statement, you should be aware of that.

> The compiler is free to inline whatever function it likes anyway, and
> in this case we do not know better than the compiler. We don't care

That's a candidate case, when we could know better than the compiler.

But "don't care" argument is still valid :)

--
With best wishes,
Vladimir