Re: [PATCH v7 2/3] PM / Domains: Add support for 'required-opps' to set default perf state
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From: Ulf Hansson <hidden>
Date: 2021-08-12 11:46:37
Also in:
linux-arm-msm, linux-devicetree, lkml
On Thu, 12 Aug 2021 at 13:28, Rajendra Nayak [off-list ref] wrote:
Some devices within power domains with performance states do not 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. runtime suspend/resume callbacks already have logic to drop/set the vote as needed and should take care of dropping the default perf state vote on runtime suspend and restore it back on runtime resume. Signed-off-by: Rajendra Nayak <redacted>
Reviewed-by: Ulf Hansson <redacted> Kind regards Uffe
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--- drivers/base/power/domain.c | 30 ++++++++++++++++++++++++++++-- include/linux/pm_domain.h | 1 + 2 files changed, 29 insertions(+), 2 deletions(-)diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index a934c67..e1c8994 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c@@ -2598,6 +2598,12 @@ 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)@@ -2637,6 +2643,7 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, { struct of_phandle_args pd_args; struct generic_pm_domain *pd; + int pstate; int ret; ret = of_parse_phandle_with_args(dev->of_node, "power-domains",@@ -2675,10 +2682,29 @@ 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; + } - return ret ? -EPROBE_DEFER : 1; + /* Set the default performance state */ + pstate = of_get_required_opp_performance_state(dev->of_node, index); + if (pstate < 0 && pstate != -ENODEV) { + ret = pstate; + goto err; + } else if (pstate > 0) { + ret = dev_pm_genpd_set_performance_state(dev, pstate); + if (ret) + goto err; + dev_gpd_data(dev)->default_pstate = pstate; + } + return 1; + +err: + dev_err(dev, "failed to set required performance state for power-domain %s: %d\n", + pd->name, ret); + genpd_remove_device(pd, dev); + return ret; } /**diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 21a0577..67017c9 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h@@ -198,6 +198,7 @@ struct generic_pm_domain_data { struct notifier_block *power_nb; int cpu; unsigned int performance_state; + unsigned int default_pstate; unsigned int rpm_pstate; ktime_t next_wakeup; void *data; --QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation