Re: [PATCH] clk: qcom: clk-alpha-pll: Replace divide operator with comparison

[Satya Priya Kakitapalli]

Hi Vladimir,


On 8/14/2024 1:31 AM, Vladimir Zapolskiy wrote:
> On 8/13/24 12:40, Satya Priya Kakitapalli wrote:
> > In zonda_pll_adjust_l_val() replace the divide operator with comparison
> > operator since comparisons are faster than divisions.
> >
> > Fixes: f4973130d255 ("clk: qcom: clk-alpha-pll: Update set_rate for 
> > Zonda PLL")
>
> Apparently the change is not a fix, therefore I believe the Fixes tag
> shall be removed.
>
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Closes: https://lore.kernel.org/r/202408110724.8pqbpDiD-lkp@xxxxxxxxx/
> > Signed-off-by: Satya Priya Kakitapalli <quic_skakitap@xxxxxxxxxxx>
> > ---
> >   drivers/clk/qcom/clk-alpha-pll.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/clk/qcom/clk-alpha-pll.c 
> > b/drivers/clk/qcom/clk-alpha-pll.c
> > index 2f620ccb41cb..fd8a82bb3690 100644
> > --- a/drivers/clk/qcom/clk-alpha-pll.c
> > +++ b/drivers/clk/qcom/clk-alpha-pll.c
> > @@ -2126,7 +2126,7 @@ static void zonda_pll_adjust_l_val(unsigned 
> > long rate, unsigned long prate, u32
> >       remainder = do_div(quotient, prate);
> >       *l = quotient;
>
> Since it's not a fix, but a simplification, you may wish to remove
> an unnecessary 'quotient' local variable:
>
> remainder = do_div(rate, prate);

I tried removing the quotient variable, but it is leading to below build 
errors on arm32 architectures, so I will add the quotient variable back 
on V3,  to make the pointer type compatible for both arm32 and arm64.


error: passing argument 1 of '__div64_32' from incompatible pointer type 
[-Werror=incompatible-pointer-types]
  238 |   __rem = __div64_32(&(n), __base);


expected 'uint64_t *' {aka 'long long unsigned int *'} but argument is 
of type 'long unsigned int *'
   24 | static inline uint32_t __div64_32(uint64_t *n, uint32_t base)


> >   -    if ((remainder * 2) / prate)
> > +    if ((remainder * 2) >= prate)
> >           *l = *l + 1;
>
> *l = rate + (u32)(remainder * 2 >= prate);
>
> I hope the assignment above is quite clear...
>
> >   }
>
> With the review comments above implemented, feel free to add to v2
>
> Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
>
> --
> Best wishes,
> Vladimir