From: Rafael J. Wysocki <rafael.j.wyso...@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_p8wxsm4dijdbho4bb6t4k50uqqvr1_cos...@mail.gmail.com/ Fixes: 21d5c57b3726 ("PM / runtime: Use device links") Reported-by: elaine.zhang <zhangq...@rock-chips.com> Diagnosed-by: Ulf Hansson <ulf.hans...@linaro.org> Reviewed-by: Ulf Hansson <ulf.hans...@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Signed-off-by: Sasha Levin <sas...@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); -- 2.30.1
