From: Rajendra Nayak <rnayak@codeaurora.org>
To: Stephen Boyd <swboyd@chromium.org>,
bjorn.andersson@linaro.org, ulf.hansson@linaro.org,
viresh.kumar@linaro.org
Cc: linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
rojay@codeaurora.org, stephan@gerhold.net
Subject: Re: [PATCH v4 1/2] PM / Domains: Add support for 'required-opps' to set default perf state
Date: Mon, 19 Jul 2021 17:20:49 +0530 [thread overview]
Message-ID: <43c77084-cfea-ef7f-8454-6f0dbc3b6577@codeaurora.org> (raw)
In-Reply-To: <CAE-0n52AkJWAL0ptFgZOrD_BXrrMte5EbZUksf5UYzBxYisCBQ@mail.gmail.com>
On 7/17/2021 1:49 AM, Stephen Boyd wrote:
> Quoting Rajendra Nayak (2021-07-16 03:00:57)
>> Some devics within power domains with performance states do not
>
> devices
>
>> support DVFS, but still need to vote on a default/static state
>> while they are active. They can express this using the 'required-opps'
>> property in device tree, which points to the phandle of the OPP
>> supported by the corresponding power-domains.
>>
>> Add support to parse this information from DT and then set the
>> specified performance state during attach and drop it on detach.
>> Also drop/set as part of runtime suspend/resume callbacks.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
>> ---
>> drivers/base/power/domain.c | 37 ++++++++++++++++++++++++++++++++++---
>> include/linux/pm_domain.h | 1 +
>> 2 files changed, 35 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>> index a934c67..dcc0b71 100644
>> --- a/drivers/base/power/domain.c
>> +++ b/drivers/base/power/domain.c
>> @@ -1000,6 +1008,8 @@ static int genpd_runtime_resume(struct device *dev)
>> genpd_stop_dev(genpd, dev);
>> err_poweroff:
>> if (!pm_runtime_is_irq_safe(dev) || genpd_is_irq_safe(genpd)) {
>> + if (default_pstate)
>> + dev_pm_genpd_set_performance_state(dev, 0);
>> genpd_lock(genpd);
>> gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
>
> Maybe this should be
>
> prev_state = genpd_drop_performance_state(dev);
> if (!default_pstate)
> gdp_data->rpm_pstate = prev_state;
>
> so we don't call dev_pm_genpd_set_performance_state() effectively twice?
> Also it would make sure we call dev_pm_genpd_set_performance_state()
> underneath the genpd_lock() if that is important. Similarly do that on
> suspend path.
looking through this more, I think I can completely drop any special
handling for default_pstate in runtime suspend and resume. The existing
drop/restore login Ulf has added should take care of it.
I'll test and respin soon.
>
>> genpd_power_off(genpd, true, 0);
>> @@ -2598,6 +2608,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)
>>
>> dev_dbg(dev, "removing from PM domain %s\n", pd->name);
>>
>> + /* Drop the default performance state */
>> + if (dev_gpd_data(dev)->default_pstate) {
>> + dev_pm_genpd_set_performance_state(dev, 0);
>> + dev_gpd_data(dev)->default_pstate = 0;
>> + }
>> +
>> for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
>> ret = genpd_remove_device(pd, dev);
>> if (ret != -EAGAIN)
>> @@ -2675,10 +2692,24 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
>> genpd_unlock(pd);
>> }
>>
>> - if (ret)
>> + if (ret) {
>> genpd_remove_device(pd, dev);
>> + return -EPROBE_DEFER;
>> + }
>> +
>> + /* Set the default performance state */
>> + np = base_dev->of_node;
>> + if (of_parse_phandle(np, "required-opps", index)) {
>> + pstate = of_get_required_opp_performance_state(np, index);
>> + if (pstate < 0) {
>> + dev_err(dev, "failed to set pstate:%d", pstate);
>
> Missing newline on printk. Also can we spell out pstate as "failed to
> set required performance state %d for power-domain %d"?
thanks, will fix when I respin.
Thanks for the review.
>
>> + ret = pstate;
>> + }
>> + dev_pm_genpd_set_performance_state(dev, pstate);
>> + dev_gpd_data(dev)->default_pstate = pstate;
>> + }
>>
>> - return ret ? -EPROBE_DEFER : 1;
>> + return ret ? ret : 1;
>> }
>>
>> /**
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
next prev parent reply other threads:[~2021-07-19 11:50 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-16 10:00 [PATCH v4 0/2] PM / Domains: Add support for 'required-opps' to set default perf state Rajendra Nayak
2021-07-16 10:00 ` [PATCH v4 1/2] " Rajendra Nayak
2021-07-16 20:19 ` Stephen Boyd
2021-07-19 11:50 ` Rajendra Nayak [this message]
2021-07-16 10:00 ` [PATCH v4 2/2] arm64: dts: sc7180: Add required-opps for i2c Rajendra Nayak
2021-07-16 19:39 ` Stephen Boyd
2021-07-16 20:18 ` Bjorn Andersson
2021-07-16 20:21 ` Stephen Boyd
2021-07-16 20:52 ` Bjorn Andersson
2021-07-16 21:49 ` Stephen Boyd
2021-07-16 21:59 ` Bjorn Andersson
2021-07-19 9:37 ` Rajendra Nayak
2021-07-19 19:19 ` Bjorn Andersson
2021-07-20 4:29 ` Rajendra Nayak
2021-07-25 17:01 ` Bjorn Andersson
2021-07-27 7:35 ` Rajendra Nayak
2021-07-28 3:46 ` Bjorn Andersson
2021-07-28 14:01 ` Dmitry Baryshkov
2021-07-28 18:47 ` Bjorn Andersson
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