Messages in this thread | | | Date | Fri, 5 Jun 2015 09:28:42 -0700 | Subject | Re: [PATCH v3 1/3] ARM: rockchip: fix the CPU soft reset | From | Doug Anderson <> |
| |
Caesar,
On Fri, Jun 5, 2015 at 8:11 AM, Caesar Wang <wxt@rock-chips.com> wrote: > We need different orderings when turning a core on and turning a core > off. In one case we need to assert reset before turning power off. > In ther other case we need to turn power on and the deassert reset. > > In general, the correct flow is: > > CPU off: > reset_control_assert > regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), BIT(pd))
Add: "ensure power domain is on" to this list.
> CPU on: > regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), 0) > reset_control_deassert
Add: "ensure power domain is on" to this list.
Adding the "ensure power domain is on" step helps document that patch set version 2 is not what you want and that you thought about it.
> @@ -88,18 +88,24 @@ static int pmu_set_power_domain(int pd, bool on) > return PTR_ERR(rstc); > } > > - if (on) > - reset_control_deassert(rstc); > - else > + if (!on) > reset_control_assert(rstc); > > - reset_control_put(rstc); > - } > + ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val); > + if (ret < 0) { > + pr_err("%s: could not update power domain\n", __func__); > + reset_control_put(rstc); > + return ret; > + } > > - ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val); > - if (ret < 0) { > - pr_err("%s: could not update power domain\n", __func__); > - return ret; > + if (on) > + reset_control_deassert(rstc);
I think you need a "reset_control_put(rstc);" here in the non-error case.
Otherwise this looks reasonable to me and you can add my Reviewed-by tag. I'll also kick off some tests with this series today to confirm as well.
-Doug
| |