Re: [PATCH V3 2/4] soc/tegra: pmc: Correct type of variable for tegra_pmc_readl()

[Laxman Dewangan]

On Thursday 05 May 2016 06:13 PM, Jon Hunter wrote:
> On 05/05/16 10:52, Laxman Dewangan wrote:
> > On Thursday 05 May 2016 03:19 PM, Jon Hunter wrote:
> > > On 04/05/16 12:39, Laxman Dewangan wrote:
> > > > The function tegra_pmc_readl() returns the u32 type data and hence
> > > > change the data type of variable where this data is stored to u32
> > > > type.
> > > >
> > > > Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
> > > >
> > > > ---
> > > > Changes from V1:
> > > > -This is new in series as per discussion on V1 series to use u32 for
> > > > tegra_pmc_readl.
> > > >
> > > > Changes from V2:
> > > > - Make unsigned long to u32 for some missed variable from V1.
> > > > ---
> > > >    drivers/soc/tegra/pmc.c | 24 ++++++++++++++----------
> > > >    1 file changed, 14 insertions(+), 10 deletions(-)
> > > >
> > > > diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> > > > index 2c3f1f9..eff9425 100644
> > > > --- a/drivers/soc/tegra/pmc.c
> > > > +++ b/drivers/soc/tegra/pmc.c
> > > > @@ -844,7 +844,8 @@ static void tegra_powergate_init(struct tegra_pmc
> > > > *pmc)
> > > >    static int tegra_io_rail_prepare(unsigned int id, unsigned long
> > > > *request,
> > > >                     unsigned long *status, unsigned int *bit)
> > > >    {
> > > > -    unsigned long rate, value;
> > > > +    unsigned long rate;
> > > > +    u32 value;
> > > >          *bit = id % 32;
> > > >    @@ -868,17 +869,18 @@ static int tegra_io_rail_prepare(unsigned int
> > > > id, unsigned long *request,
> > > >        tegra_pmc_writel(DPD_SAMPLE_ENABLE, DPD_SAMPLE);
> > > >          /* must be at least 200 ns, in APB (PCLK) clock cycles */
> > > > -    value = DIV_ROUND_UP(1000000000, rate);
> > > > -    value = DIV_ROUND_UP(200, value);
> > > > +    rate = DIV_ROUND_UP(1000000000, rate);
> > > > +    rate = DIV_ROUND_UP(200, rate);
> > > > +    value = (u32)rate;
> > > Although it is unlikely, I think that we should check it is less
> > > than U32_MAX, return an error if it is not.
> > rate = DIV_ROUNC_UP(200, rate) means
> >
> > rate = (200 + rate -1)/rate
> >
> > and can not be more than 200 in any case (if rate =1).
> > So no need of the error check.
> OK, yes you are right. In that case there is no need to cast and so I
> would leave this code as-is and not change the type.

You mean keep value as unsigned long for value?

I think we can still say value as u32 and simply write
value = rate


Just remove the casting.