linux-kernel - [PATCH 1/3] PM: domains: Drop the performance state vote for a device at detach

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu,  2 Sep 2021 12:16:32 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Dmitry Osipenko <digetx@...il.com>, linux-pm@...r.kernel.org
Cc:     Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Thierry Reding <thierry.reding@...il.com>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Stephan Gerhold <stephan@...hold.net>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Ulf Hansson <ulf.hansson@...aro.org>
Subject: [PATCH 1/3] PM: domains: Drop the performance state vote for a device at detach

When a device is detached from its genpd, genpd loses track of the device,
including its performance state vote that may have been requested for it.

Rather than relying on the consumer driver to drop the performance state
vote for its device, let's do it internally in genpd when the device is
getting detached. In this way, we makes sure that the aggregation of the
votes in genpd becomes correct.

Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
---
 drivers/base/power/domain.c | 9 ++-------
 include/linux/pm_domain.h   | 1 -
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 5db704f02e71..278e040f607f 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1665,6 +1665,8 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
 		goto out;
 	}
 
+	genpd_set_performance_state(dev, 0);
+
 	genpd->device_count--;
 	genpd->max_off_time_changed = true;
 
@@ -2604,12 +2606,6 @@ 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)
@@ -2702,7 +2698,6 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 		ret = dev_pm_genpd_set_performance_state(dev, pstate);
 		if (ret)
 			goto err;
-		dev_gpd_data(dev)->default_pstate = pstate;
 	}
 	return 1;
 
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 67017c9390c8..21a0577305ef 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -198,7 +198,6 @@ 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;
-- 
2.25.1