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@xxxxxxxxxxxxxx>
---
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;
}
/**
--
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