From: Rafael J. Wysocki rafael.j.wysocki@intel.com
[ Upstream commit 5244f5e2d801259af877ee759e8c22364c607072 ]
Because the PM-runtime status of the device is not updated in __rpm_callback(), attempts to suspend the suppliers of the given device triggered by the rpm_put_suppliers() call in there may cause a supplier to be suspended completely before the status of the consumer is updated to RPM_SUSPENDED, which is confusing.
To avoid that (1) modify __rpm_callback() to only decrease the PM-runtime usage counter of each supplier and (2) make rpm_suspend() try to suspend the suppliers after changing the consumer's status to RPM_SUSPENDED, in analogy with the device's parent.
Link: https://lore.kernel.org/linux-pm/CAPDyKFqm06KDw_p8WXsM4dijDbho4bb6T4k50UqqvR... Fixes: 21d5c57b3726 ("PM / runtime: Use device links") Reported-by: elaine.zhang zhangqing@rock-chips.com Diagnosed-by: Ulf Hansson ulf.hansson@linaro.org Reviewed-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/power/runtime.c | 45 +++++++++++++++++++++++++++++++----- 1 file changed, 39 insertions(+), 6 deletions(-)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index bfda153b1a41..5ef67bacb585 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -305,7 +305,7 @@ static int rpm_get_suppliers(struct device *dev) return 0; }
-static void rpm_put_suppliers(struct device *dev) +static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend) { struct device_link *link;
@@ -313,10 +313,30 @@ static void rpm_put_suppliers(struct device *dev) device_links_read_lock_held()) {
while (refcount_dec_not_one(&link->rpm_active)) - pm_runtime_put(link->supplier); + pm_runtime_put_noidle(link->supplier); + + if (try_to_suspend) + pm_request_idle(link->supplier); } }
+static void rpm_put_suppliers(struct device *dev) +{ + __rpm_put_suppliers(dev, true); +} + +static void rpm_suspend_suppliers(struct device *dev) +{ + struct device_link *link; + int idx = device_links_read_lock(); + + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, + device_links_read_lock_held()) + pm_request_idle(link->supplier); + + device_links_read_unlock(idx); +} + /** * __rpm_callback - Run a given runtime PM callback for a given device. * @cb: Runtime PM callback to run. @@ -344,8 +364,10 @@ static int __rpm_callback(int (*cb)(struct device *), struct device *dev) idx = device_links_read_lock();
retval = rpm_get_suppliers(dev); - if (retval) + if (retval) { + rpm_put_suppliers(dev); goto fail; + }
device_links_read_unlock(idx); } @@ -368,9 +390,9 @@ static int __rpm_callback(int (*cb)(struct device *), struct device *dev) || (dev->power.runtime_status == RPM_RESUMING && retval))) { idx = device_links_read_lock();
- fail: - rpm_put_suppliers(dev); + __rpm_put_suppliers(dev, false);
+fail: device_links_read_unlock(idx); }
@@ -642,8 +664,11 @@ static int rpm_suspend(struct device *dev, int rpmflags) goto out; }
+ if (dev->power.irq_safe) + goto out; + /* Maybe the parent is now able to suspend. */ - if (parent && !parent->power.ignore_children && !dev->power.irq_safe) { + if (parent && !parent->power.ignore_children) { spin_unlock(&dev->power.lock);
spin_lock(&parent->power.lock); @@ -652,6 +677,14 @@ static int rpm_suspend(struct device *dev, int rpmflags)
spin_lock(&dev->power.lock); } + /* Maybe the suppliers are now able to suspend. */ + if (dev->power.links_count > 0) { + spin_unlock_irq(&dev->power.lock); + + rpm_suspend_suppliers(dev); + + spin_lock_irq(&dev->power.lock); + }
out: trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);