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Groups > linux.kernel > #1438409
| From | Laxman Dewangan <ldewangan@nvidia.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode |
| Date | 2016-07-07 11:00 +0200 |
| Message-ID | <rSdk7-4BD-33@gated-at.bofh.it> (permalink) |
| References | <rS03v-4kw-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thursday 07 July 2016 12:12 AM, Douglas Anderson wrote:
> The original commit adding support for continuous voltage mode didn't
> handle the regulator ramp delay properly. It treated the delay as a
> fixed delay in uS despite the property being defined as uV / uS. Let's
> adjust it. Luckily there appear to be no users of this ramp delay for
> PWM regulators (as per grepping through device trees in linuxnext).
>
> Note also that the upper bound of usleep_range probably shouldn't be a
> full 1 ms longer than the lower bound since I've seen plenty of hardware
> with a ramp rate of ~5000 uS / uV and for small jumps the total delays
> are in the tens of uS. 1000 is way too much. We'll try to be dynamic
> and use 10%.
>
> NOTE: This commit doesn't add support for regulator-enable-ramp-delay.
> That could be done in a future patch when someone has a user of that
> featre.
>
> Though this patch is shows as "fixing" a bug, there are no actual known
> users of continuous mode PWM regulator w/ ramp delay in mainline and so
> this likely won't have any effect on anyone unless they are working
> out-of-tree with private patches. For anyone in this state, it is
> highly encouraged to also pick Boris Brezillon's WIP patches to get
> yourself a reliable and glitch-free regulator.
>
> Fixes: 4773be185a0f ("regulator: pwm-regulator: Add support for continuous-voltage")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
Looks fine here.
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
BTW, for some PWM regulator, the settling time for voltage change is
same for any steps.
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[PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode Douglas Anderson <dianders@chromium.org> - 2016-07-06 20:50 +0200
Re: [PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode Laxman Dewangan <ldewangan@nvidia.com> - 2016-07-07 11:00 +0200
Re: [PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode Doug Anderson <dianders@chromium.org> - 2016-07-07 18:40 +0200
RE: [PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode Aleksandr Frid <afrid@nvidia.com> - 2016-07-07 20:30 +0200
Re: [PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode Doug Anderson <dianders@chromium.org> - 2016-07-07 20:40 +0200
RE: [PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode Aleksandr Frid <afrid@nvidia.com> - 2016-07-07 20:50 +0200
Re: [PATCH v2] regulator: pwm: Fix regulator ramp delay for continuous mode Mark Brown <broonie@kernel.org> - 2016-07-08 11:00 +0200
Applied "regulator: pwm: Fix regulator ramp delay for continuous mode" to the regulator tree Mark Brown <broonie@kernel.org> - 2016-07-07 12:10 +0200
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