linux-kernel - [RFC 5/7] PM / Domains: succeed & warn when attaching non-irqsafe devices to an irq-safe domain.

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Date:	Fri, 25 Sep 2015 15:04:07 +0200
From:	Marc Titinger <mtitinger@...libre.com>
To:	khilman@...nel.org, rjw@...ysocki.net
Cc:	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
	ahaslam@...libre.com, bcousson@...libre.com, lina.iyer@...aro.org,
	Marc Titinger <mtitinger@...libre.com>
Subject: [RFC 5/7] PM / Domains: succeed & warn when attaching non-irqsafe devices to an irq-safe domain.

From: Marc Titinger <mtitinger@...libre.com>

This patch checks for irq-safe compatibility in suspend/resume instead of
failing the attach operation early on. Non-cpu devices attaching to an
irq-safe power domain will have to call pm_runtime_irq_safe from their
probe function.

Signed-off-by: Marc Titinger <mtitinger@...libre.com>
---
 drivers/base/power/domain.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 8259654..b747e9e 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -585,6 +585,14 @@ static int pm_genpd_runtime_suspend(struct device *dev)
 	if (dev->power.irq_safe && !genpd->irq_safe)
 		return 0;
 
+	/* The device probe may have missed calling pm_runtime_irq_safe.
+	 */
+	if (!dev->power.irq_safe && genpd->irq_safe) {
+		dev_err(dev, "trying to %s a non-irqsafe device in an irq-safe domain\n",
+		__func__);
+		return -EINVAL;
+	}
+
 	genpd_lock(genpd);
 
 	genpd->in_progress++;
@@ -624,6 +632,14 @@ static int pm_genpd_runtime_resume(struct device *dev)
 		goto out;
 	}
 
+	/* The device probe may have missed calling pm_runtime_irq_safe.
+	 */
+	if (!dev->power.irq_safe && genpd->irq_safe) {
+		dev_err(dev, "trying to %s a non-irqsafe device in an irq-safe domain\n",
+		__func__);
+		return -EINVAL;
+	}
+
 	genpd_lock(genpd);
 	ret = __pm_genpd_poweron(genpd);
 	genpd_unlock(genpd);
@@ -1365,11 +1381,11 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
 		return -EINVAL;
 
-	if (genpd->irq_safe && !dev->power.irq_safe) {
-		dev_err(dev,
+	/* Only issue a warning, runtime_irqsafe may be called later on
+	 * from the driver probe. */
+	if (genpd->irq_safe && !dev->power.irq_safe)
+		dev_warn(dev,
 			"Devices in an IRQ safe domain have to be IRQ safe.\n");
-		return -EINVAL;
-	}
 
 	gpd_data = genpd_alloc_dev_data(dev, genpd, td);
 	if (IS_ERR(gpd_data))
-- 
1.9.1

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