diff options
author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-02-07 19:38:56 +0100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-08 11:26:14 +0100 |
commit | 4080ab083000a1e9656b0d1607e238e7001e0c84 (patch) | |
tree | eac34432ee6a46348a1a41bc277df934ef71aa19 /drivers/base | |
parent | 79a4e91d1bb2a411a4ce2baa93680fa707567003 (diff) | |
download | linux-4080ab083000a1e9656b0d1607e238e7001e0c84.tar.bz2 |
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>
Diffstat (limited to 'drivers/base')
-rw-r--r-- | drivers/base/power/runtime.c | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index fd5c4a7b96f0..a0e55065817b 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); |