Re: [PATCH] riscv: Fix udelay in RV32.
From: Nick Hu
Date: Thu May 30 2019 - 02:36:39 EST
On Thu, May 30, 2019 at 01:52:58PM +0800, Christoph Hellwig wrote:
> On Tue, May 28, 2019 at 05:26:49PM +0800, Nick Hu wrote:
> > In RV32, udelay would delay the wrong cycle.
> > When it shifts right "UDELAY_SHITFT" bits, it
> > either delays 0 cycle or 1 cycle. It only works
> > correctly in RV64. Because the 'ucycles' always
> > needs to be 64 bits variable.
>
> Please use up all your ~72 chars per line in the commit log.
>
OK, Thanks!
> > diff --git a/arch/riscv/lib/delay.c b/arch/riscv/lib/delay.c
> > index dce8ae24c6d3..da847f49fb74 100644
> > --- a/arch/riscv/lib/delay.c
> > +++ b/arch/riscv/lib/delay.c
> > @@ -88,7 +88,7 @@ EXPORT_SYMBOL(__delay);
> >
> > void udelay(unsigned long usecs)
> > {
> > - unsigned long ucycles = usecs * lpj_fine * UDELAY_MULT;
> > + unsigned long long ucycles = (unsigned long long)usecs * lpj_fine * UDELAY_MULT;
>
> And this creates a way too long line. Pleaase use u64 instead of
> unsigned long long to clarify the intention while also fixing the long
> lines.
>
Sure, I will fix it and send another patch. Thanks.
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