On Mon, Dec 05, 2016 at 02:05:21PM -0600, Grygorii Strashko wrote:
> @@ -372,34 +354,27 @@ void cpts_tx_timestamp(struct cpts *cpts, struct 
> sk_buff *skb)
>  }
>  EXPORT_SYMBOL_GPL(cpts_tx_timestamp);
>  
> -int cpts_register(struct device *dev, struct cpts *cpts,
> -               u32 mult, u32 shift)
> +int cpts_register(struct cpts *cpts)
>  {
>       int err, i;
>  
> -     cpts->info = cpts_info;
> -     spin_lock_init(&cpts->lock);
> -
> -     cpts->cc.read = cpts_systim_read;
> -     cpts->cc.mask = CLOCKSOURCE_MASK(32);
> -     cpts->cc_mult = mult;
> -     cpts->cc.mult = mult;
> -     cpts->cc.shift = shift;
> -
>       INIT_LIST_HEAD(&cpts->events);
>       INIT_LIST_HEAD(&cpts->pool);
>       for (i = 0; i < CPTS_MAX_EVENTS; i++)
>               list_add(&cpts->pool_data[i].list, &cpts->pool);
>  
> -     cpts_clk_init(dev, cpts);
> +     clk_enable(cpts->refclk);
> +
>       cpts_write32(cpts, CPTS_EN, control);
>       cpts_write32(cpts, TS_PEND_EN, int_enable);
>  
> +     /* reinitialize cc.mult to original value as it can be modified
> +      * by cpts_ptp_adjfreq().
> +      */
> +     cpts->cc.mult = cpts->cc_mult;

This still isn't quite right.  First of all, you shouldn't clobber the
learned cc.mult value in cpts_register().  Presumably, if PTP had been
run on this port before, then the learned frequency is approximately
correct, and it should be left alone.

[ BTW, resetting the timecounter here makes no sense either.  Why
  reset the clock just because the interface goes down?  ]

Secondly, you have made the initialization order of these fields hard
to follow.  With the whole series applied:

probe()
        cpts_create()
                cpts_of_parse()
                {
                        /* Set cc_mult but not cc.mult! */
                        set cc_mult
                        set cc.shift
                }
                cpts_calc_mult_shift()
                {
                        /* Set them both. */
                        cpts->cc_mult = mult;
                        cpts->cc.mult = mult;
                        cpts->cc.shift = shift;
                }
/* later on */
cpts_register()
        cpts->cc.mult = cpts->cc_mult;

There is no need for such complexity.  Simply set cc.mult in
cpts_create() _once_, immediately after the call to
cpts_calc_mult_shift().

You can remove the assignment from cpts_calc_mult_shift() and
cpts_register().

Thanks,
Richard

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