diff options
Diffstat (limited to 'drivers/base/power/runtime.c')
-rw-r--r-- | drivers/base/power/runtime.c | 101 |
1 files changed, 74 insertions, 27 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 78937c45278c..a80dbf08a99c 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -282,11 +282,8 @@ static int rpm_get_suppliers(struct device *dev) list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) { int retval; - if (!(link->flags & DL_FLAG_PM_RUNTIME)) - continue; - - if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND || - link->rpm_active) + if (!(link->flags & DL_FLAG_PM_RUNTIME) || + READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND) continue; retval = pm_runtime_get_sync(link->supplier); @@ -295,7 +292,7 @@ static int rpm_get_suppliers(struct device *dev) pm_runtime_put_noidle(link->supplier); return retval; } - link->rpm_active = true; + refcount_inc(&link->rpm_active); } return 0; } @@ -304,12 +301,13 @@ static void rpm_put_suppliers(struct device *dev) { struct device_link *link; - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) - if (link->rpm_active && - READ_ONCE(link->status) != DL_STATE_SUPPLIER_UNBIND) { + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) { + if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND) + continue; + + while (refcount_dec_not_one(&link->rpm_active)) pm_runtime_put(link->supplier); - link->rpm_active = false; - } + } } /** @@ -1114,24 +1112,57 @@ 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); + spin_lock_irq(&dev->power.lock); - if (!dev->power.runtime_error && !dev->power.disable_depth) { + /* + * Prevent PM-runtime from being enabled for the device or return an + * error if it is enabled already and working. + */ + if (dev->power.runtime_error || dev->power.disable_depth) + dev->power.disable_depth++; + else error = -EAGAIN; - goto out; + + spin_unlock_irq(&dev->power.lock); + + if (error) + return error; + + /* + * 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_status == status || !parent) goto out_set; @@ -1159,19 +1190,33 @@ 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); + } + + pm_runtime_enable(dev); + return error; } EXPORT_SYMBOL_GPL(__pm_runtime_set_status); @@ -1569,7 +1614,7 @@ void pm_runtime_remove(struct device *dev) * * Check links from this device to any consumers and if any of them have active * runtime PM references to the device, drop the usage counter of the device - * (once per link). + * (as many times as needed). * * Links with the DL_FLAG_STATELESS flag set are ignored. * @@ -1591,10 +1636,8 @@ void pm_runtime_clean_up_links(struct device *dev) if (link->flags & DL_FLAG_STATELESS) continue; - if (link->rpm_active) { + while (refcount_dec_not_one(&link->rpm_active)) pm_runtime_put_noidle(dev); - link->rpm_active = false; - } } device_links_read_unlock(idx); @@ -1612,8 +1655,11 @@ void pm_runtime_get_suppliers(struct device *dev) idx = device_links_read_lock(); list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) - if (link->flags & DL_FLAG_PM_RUNTIME) + if (link->flags & DL_FLAG_PM_RUNTIME) { + link->supplier_preactivated = true; + refcount_inc(&link->rpm_active); pm_runtime_get_sync(link->supplier); + } device_links_read_unlock(idx); } @@ -1630,8 +1676,11 @@ void pm_runtime_put_suppliers(struct device *dev) idx = device_links_read_lock(); list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) - if (link->flags & DL_FLAG_PM_RUNTIME) - pm_runtime_put(link->supplier); + if (link->supplier_preactivated) { + link->supplier_preactivated = false; + if (refcount_dec_not_one(&link->rpm_active)) + pm_runtime_put(link->supplier); + } device_links_read_unlock(idx); } @@ -1645,8 +1694,6 @@ void pm_runtime_new_link(struct device *dev) void pm_runtime_drop_link(struct device *dev) { - rpm_put_suppliers(dev); - spin_lock_irq(&dev->power.lock); WARN_ON(dev->power.links_count == 0); dev->power.links_count--; |