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Date:   Thu, 30 May 2019 14:32:32 +0800
From:   Nick Hu <nickhu@andestech.com>
To:     Christoph Hellwig <hch@infradead.org>
CC:     "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>,
        "palmer@sifive.com" <palmer@sifive.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "green.hu@gmail.com" <green.hu@gmail.com>,
        Greentime Ying-Han =?utf-8?B?SHUo6IOh6Iux5ryiKQ==?= 
        <greentime@andestech.com>
Subject: Re: [PATCH] riscv: Fix udelay in RV32.
Message-ID: <20190530063232.GA17102@andestech.com>
References: <381ee6950c84b868ca6a3c676eb981a1980889a3.1559035050.git.nickhu@andestech.com>
 <20190530055258.GA7170@infradead.org>
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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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