Re: [PATCH v4 12/24] PM / devfreq: tegra30: Inline all one-line functions

[Dmitry Osipenko]

Ð Thu, 18 Jul 2019 18:09:05 +0900
Chanwoo Choi <cw00.choi@xxxxxxxxxxx> ÐÐÑÐÑ:

> On 19. 7. 16. ìí 10:35, Dmitry Osipenko wrote:
> > 16.07.2019 15:26, Chanwoo Choi ÐÐÑÐÑ:  
> >> Hi Dmitry,
> >>
> >> I'm not sure that it is necessary.
> >> As I knew, usally, the 'inline' is used on header file
> >> to define the empty functions.
> >>
> >> Do we have to change it with 'inline' keyword?  
> > 
> > The 'inline' attribute tells compiler that instead of jumping into
> > the function, it should take the function's code and replace the
> > function's invocation with that code. This is done in order to help
> > compiler optimize code properly, please see [1]. There is
> > absolutely no need to create a function call into a function that
> > consists of a single instruction.
> > 
> > [1] https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Inline.html
> >   
> 
> If you want to add 'inline' keyword, I recommend that 
> you better to remove the modified function in this patch
> and then just call the 'write_relaxed or read_relaxed' function
> directly. It is same result when using inline keyword.

That could be done, but it makes code less readable.

See the difference:

device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);

writel_relaxed(ACTMON_INTR_STATUS_CLEAR,
	       dev->regs + ACTMON_DEV_INTR_STATUS);