Re: [PATCH v2 12/13] net: ethernet: ti: cpts: calc mult and shift from refclk freq

From: Richard Cochran
Date: Tue Nov 29 2016 - 05:35:14 EST


On Mon, Nov 28, 2016 at 05:03:36PM -0600, Grygorii Strashko wrote:
> +static void cpts_calc_mult_shift(struct cpts *cpts)
> +{
> + u64 frac, maxsec, ns;
> + u32 freq, mult, shift;
> +
> + freq = clk_get_rate(cpts->refclk);
> +
> + /* Calc the maximum number of seconds which we can run before
> + * wrapping around.
> + */
> + maxsec = cpts->cc.mask;
> + do_div(maxsec, freq);
> + if (maxsec > 600 && cpts->cc.mask > UINT_MAX)
> + maxsec = 600;

The reason for this test is not obvious. Why check cc.mask against
UINT_MAX? Please use the comment to explain it.

Thanks,
Richard