Hi Stephen,
On Tue, Mar 30, 2021 at 4:22 AM Stephen Boyd <sboyd@xxxxxxxxxx> wrote:
> Quoting Geert Uytterhoeven (2021-03-26 05:00:59)
> > +}
> > +
> > +static int cpg_pll_clk_set_rate(struct clk_hw *hw, unsigned long rate,
> > + unsigned long parent_rate)
> > +{
> > + struct cpg_pll_clk *pll_clk = to_pll_clk(hw);
> > + unsigned int mult, i;
> > + u32 val;
> > +
> > + mult = DIV_ROUND_CLOSEST_ULL(rate, parent_rate * pll_clk->fixed_mult);
> > + mult = clamp(mult, 1U, 128U);
> > +
> > + val = readl(pll_clk->pllcr_reg);
> > + val &= ~CPG_PLLnCR_STC_MASK;
> > + val |= (mult - 1) << __ffs(CPG_PLLnCR_STC_MASK);
> > + writel(val, pll_clk->pllcr_reg);
> > +
> > + for (i = 1000; i; i--) {
> > + if (readl(pll_clk->pllecr_reg) & pll_clk->pllecr_pllst_mask)
> > + return 0;
> > +
> > + cpu_relax();
> > + }
>
> Why not readl_poll_timeout()?
I had considered that. But then I noticed readl_poll_timeout() does not
call cpu_relax() if sleep_us == 0. Perhaps such a call should be added
(at the risk of introducing a subtle regression elsewhere)?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
