Re: [PATCH v7 10/10] pwm: dwc: use clock rate in hz to avoid rounding issues

From: Ben Dooks
Date: Wed Jun 14 2023 - 07:18:17 EST


On 16/02/2023 21:39, Uwe Kleine-König wrote:
On Fri, Dec 23, 2022 at 03:38:20PM +0000, Ben Dooks wrote:
As noted, the clock-rate when not a nice multiple of ns is probably
going to end up with inacurate caculations, as well as on a non pci

Given that such a non-nice ca*l*culation only happens in the of case
that is introduced here, it would be nice to move this patch before the
introduction of the of-support.

I've moved of support to the end of the series
you
system the rate may change (although we've not put a clock rate
change notifier in this code yet) so we also add some quick checks
of the rate when we do any calculations with it.

If the clk rate changes while the PWM is on, this modifies the output.
This is unfortunate and so it justifies adding a call to
clk_rate_exclusive_get() when the PWM is on.

I can't really test things any more as the hardware has been returned
to the client and I'm technically off the project (and awaiting this
email address to be closed down).

Could this either be solved by the clk_rate_exclusive_get() or adding
a clock change notifier? Either way I would prefer this to be work for
another patch.

I'll send v8 out later as it has had some re-works due to moving
things around.

Thank you for the review.

--
Ben