linux-kernel - [PATCH 2/3] PM / Domains: Allow OF lookup for multi PM domain case from ->attach

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Date:   Thu, 18 Apr 2019 12:27:56 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     "Rafael J . Wysocki" <rjw@...ysocki.net>, linux-pm@...r.kernel.org
Cc:     Ulf Hansson <ulf.hansson@...aro.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jon Hunter <jonathanh@...dia.com>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Niklas Cassel <niklas.cassel@...aro.org>,
        Kevin Hilman <khilman@...nel.org>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: [PATCH 2/3] PM / Domains: Allow OF lookup for multi PM domain case from ->attach_dev()

A genpd provider that uses the ->attach_dev() callback to lookup resources
for a device, fails to do so when the device has multiple PM domains. This
is because when genpd invokes the ->attach_dev() callback, it passes the
allocated virtual device as the in-parameter.

To address this problem, let's simply assign the dev->of_node for the
virtual device, based upon the original device's OF node.

Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
---
 drivers/base/power/domain.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 7fec69aebf46..801f31c87d16 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2345,6 +2345,7 @@ EXPORT_SYMBOL_GPL(of_genpd_remove_last);
 
 static void genpd_release_dev(struct device *dev)
 {
+	of_node_put(dev->of_node);
 	kfree(dev);
 }
 
@@ -2406,14 +2407,14 @@ static void genpd_dev_pm_sync(struct device *dev)
 	genpd_queue_power_off_work(pd);
 }
 
-static int __genpd_dev_pm_attach(struct device *dev, struct device_node *np,
-				 unsigned int index, bool power_on)
+static int __genpd_dev_pm_attach(struct device *dev, unsigned int index,
+				 bool power_on)
 {
 	struct of_phandle_args pd_args;
 	struct generic_pm_domain *pd;
 	int ret;
 
-	ret = of_parse_phandle_with_args(np, "power-domains",
+	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
 				"#power-domain-cells", index, &pd_args);
 	if (ret < 0)
 		return ret;
@@ -2481,7 +2482,7 @@ int genpd_dev_pm_attach(struct device *dev)
 				       "#power-domain-cells") != 1)
 		return 0;
 
-	return __genpd_dev_pm_attach(dev, dev->of_node, 0, true);
+	return __genpd_dev_pm_attach(dev, 0, true);
 }
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
 
@@ -2525,6 +2526,7 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev,
 	dev_set_name(virt_dev, "genpd:%u:%s", index, dev_name(dev));
 	virt_dev->bus = &genpd_bus_type;
 	virt_dev->release = genpd_release_dev;
+	virt_dev->of_node = of_node_get(dev->of_node);
 
 	ret = device_register(virt_dev);
 	if (ret) {
@@ -2533,7 +2535,7 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev,
 	}
 
 	/* Try to attach the device to the PM domain at the specified index. */
-	ret = __genpd_dev_pm_attach(virt_dev, dev->of_node, index, false);
+	ret = __genpd_dev_pm_attach(virt_dev, index, false);
 	if (ret < 1) {
 		device_unregister(virt_dev);
 		return ret ? ERR_PTR(ret) : NULL;
-- 
2.17.1