From 4080ab083000a1e9656b0d1607e238e7001e0c84 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Thu, 7 Feb 2019 19:38:56 +0100
Subject: [PATCH] PM-runtime: Take suppliers into account in
__pm_runtime_set_status()
If the target device has any suppliers, as reflected by device links
to them, __pm_runtime_set_status() does not take them into account,
which is not consistent with the other parts of the PM-runtime
framework and may lead to programming mistakes.
Modify __pm_runtime_set_status() to take suppliers into account by
activating them upfront if the new status is RPM_ACTIVE and
deactivating them on exit if the new status is RPM_SUSPENDED.
If the activation of one of the suppliers fails, the new status
will be RPM_SUSPENDED and the (remaining) suppliers will be
deactivated on exit (the child count of the device's parent
will be dropped too then).
Of course, adding device links locking to __pm_runtime_set_status()
means that it cannot be run fron interrupt context, so make it use
spin_lock_irq() and spin_unlock_irq() instead of spin_lock_irqsave()
and spin_unlock_irqrestore(), respectively.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/base/power/runtime.c | 45 ++++++++++++++++++++++++++++++++----
1 file changed, 40 insertions(+), 5 deletions(-)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index fd5c4a7b96f0d..a0e55065817bb 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1089,20 +1089,43 @@ EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
* and the device parent's counter of unsuspended children is modified to
* reflect the new status. If the new status is RPM_SUSPENDED, an idle
* notification request for the parent is submitted.
+ *
+ * If @dev has any suppliers (as reflected by device links to them), and @status
+ * is RPM_ACTIVE, they will be activated upfront and if the activation of one
+ * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead
+ * of the @status value) and the suppliers will be deacticated on exit. The
+ * error returned by the failing supplier activation will be returned in that
+ * case.
*/
int __pm_runtime_set_status(struct device *dev, unsigned int status)
{
struct device *parent = dev->parent;
- unsigned long flags;
bool notify_parent = false;
int error = 0;
if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
return -EINVAL;
- spin_lock_irqsave(&dev->power.lock, flags);
+ /*
+ * If the new status is RPM_ACTIVE, the suppliers can be activated
+ * upfront regardless of the current status, because next time
+ * rpm_put_suppliers() runs, the rpm_active refcounts of the links
+ * involved will be dropped down to one anyway.
+ */
+ if (status == RPM_ACTIVE) {
+ int idx = device_links_read_lock();
+
+ error = rpm_get_suppliers(dev);
+ if (error)
+ status = RPM_SUSPENDED;
+
+ device_links_read_unlock(idx);
+ }
+
+ spin_lock_irq(&dev->power.lock);
if (!dev->power.runtime_error && !dev->power.disable_depth) {
+ status = dev->power.runtime_status;
error = -EAGAIN;
goto out;
}
@@ -1134,19 +1157,31 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status)
spin_unlock(&parent->power.lock);
- if (error)
+ if (error) {
+ status = RPM_SUSPENDED;
goto out;
+ }
}
out_set:
__update_runtime_status(dev, status);
- dev->power.runtime_error = 0;
+ if (!error)
+ dev->power.runtime_error = 0;
+
out:
- spin_unlock_irqrestore(&dev->power.lock, flags);
+ spin_unlock_irq(&dev->power.lock);
if (notify_parent)
pm_request_idle(parent);
+ if (status == RPM_SUSPENDED) {
+ int idx = device_links_read_lock();
+
+ rpm_put_suppliers(dev);
+
+ device_links_read_unlock(idx);
+ }
+
return error;
}
EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
--
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