Re: [PATCH v2 2/2] clk: mediatek: Add MT8173 MMPLL change rate support

From: James Liao
Date: Fri Jul 10 2015 - 01:46:54 EST


Hi Stephen,

On Wed, 2015-07-08 at 17:46 -0700, Stephen Boyd wrote:
> On 07/08/2015 01:37 AM, James Liao wrote:
> > diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
> > index 68af518..622e7b6 100644
> > --- a/drivers/clk/mediatek/clk-pll.c
> > +++ b/drivers/clk/mediatek/clk-pll.c
> > @@ -138,16 +138,28 @@ static void mtk_pll_calc_values(struct mtk_clk_pll *pll, u32 *pcw, u32 *postdiv,
> > u32 freq, u32 fin)
> > {
> > unsigned long fmin = 1000 * MHZ;
> > + const struct mtk_pll_div_table *div_table = pll->data->div_table;
> > u64 _pcw;
> > u32 val;
> >
> > if (freq > pll->data->fmax)
> > freq = pll->data->fmax;
> >
> > - for (val = 0; val < 4; val++) {
> > + if (div_table) {
> > + if (freq > div_table[0].freq)
> > + freq = div_table[0].freq;
> > +
> > + for (val = 0; div_table[val + 1].freq != 0; val++) {
> > + if (freq > div_table[val + 1].freq)
> > + break;
> > + }
> > *postdiv = 1 << val;
> > - if (freq * *postdiv >= fmin)
> > - break;
> > + } else {
> > + for (val = 0; val < 5; val++) {
> > + *postdiv = 1 << val;
> > + if ((u64)freq * *postdiv >= fmin)
> >
>
> No mention of this cast in the commit text. Is this fixing a bug? If so,
> please mention it and/or split this bug fix off of this patch.
>

Yes, this is a fix to avoid u32 overflow. I'll split it in next patch.


Best regards,

James


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