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path: root/drivers/usb/core/offload.c
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Diffstat (limited to 'drivers/usb/core/offload.c')
-rw-r--r--drivers/usb/core/offload.c102
1 files changed, 59 insertions, 43 deletions
diff --git a/drivers/usb/core/offload.c b/drivers/usb/core/offload.c
index 7c699f1b8d2b..9db3cfedd29c 100644
--- a/drivers/usb/core/offload.c
+++ b/drivers/usb/core/offload.c
@@ -25,33 +25,30 @@
*/
int usb_offload_get(struct usb_device *udev)
{
- int ret;
+ int ret = 0;
- usb_lock_device(udev);
- if (udev->state == USB_STATE_NOTATTACHED) {
- usb_unlock_device(udev);
+ if (!usb_get_dev(udev))
return -ENODEV;
- }
- if (udev->state == USB_STATE_SUSPENDED ||
- udev->offload_at_suspend) {
- usb_unlock_device(udev);
- return -EBUSY;
+ if (pm_runtime_get_if_active(&udev->dev) != 1) {
+ ret = -EBUSY;
+ goto err_rpm;
}
- /*
- * offload_usage could only be modified when the device is active, since
- * it will alter the suspend flow of the device.
- */
- ret = usb_autoresume_device(udev);
- if (ret < 0) {
- usb_unlock_device(udev);
- return ret;
+ spin_lock(&udev->offload_lock);
+
+ if (udev->offload_pm_locked) {
+ ret = -EAGAIN;
+ goto err;
}
udev->offload_usage++;
- usb_autosuspend_device(udev);
- usb_unlock_device(udev);
+
+err:
+ spin_unlock(&udev->offload_lock);
+ pm_runtime_put_autosuspend(&udev->dev);
+err_rpm:
+ usb_put_dev(udev);
return ret;
}
@@ -69,35 +66,32 @@ EXPORT_SYMBOL_GPL(usb_offload_get);
*/
int usb_offload_put(struct usb_device *udev)
{
- int ret;
+ int ret = 0;
- usb_lock_device(udev);
- if (udev->state == USB_STATE_NOTATTACHED) {
- usb_unlock_device(udev);
+ if (!usb_get_dev(udev))
return -ENODEV;
- }
- if (udev->state == USB_STATE_SUSPENDED ||
- udev->offload_at_suspend) {
- usb_unlock_device(udev);
- return -EBUSY;
+ if (pm_runtime_get_if_active(&udev->dev) != 1) {
+ ret = -EBUSY;
+ goto err_rpm;
}
- /*
- * offload_usage could only be modified when the device is active, since
- * it will alter the suspend flow of the device.
- */
- ret = usb_autoresume_device(udev);
- if (ret < 0) {
- usb_unlock_device(udev);
- return ret;
+ spin_lock(&udev->offload_lock);
+
+ if (udev->offload_pm_locked) {
+ ret = -EAGAIN;
+ goto err;
}
/* Drop the count when it wasn't 0, ignore the operation otherwise. */
if (udev->offload_usage)
udev->offload_usage--;
- usb_autosuspend_device(udev);
- usb_unlock_device(udev);
+
+err:
+ spin_unlock(&udev->offload_lock);
+ pm_runtime_put_autosuspend(&udev->dev);
+err_rpm:
+ usb_put_dev(udev);
return ret;
}
@@ -112,25 +106,47 @@ EXPORT_SYMBOL_GPL(usb_offload_put);
* management.
*
* The caller must hold @udev's device lock. In addition, the caller should
- * ensure downstream usb devices are all either suspended or marked as
- * "offload_at_suspend" to ensure the correctness of the return value.
+ * ensure the device itself and the downstream usb devices are all marked as
+ * "offload_pm_locked" to ensure the correctness of the return value.
*
* Returns true on any offload activity, false otherwise.
*/
bool usb_offload_check(struct usb_device *udev) __must_hold(&udev->dev->mutex)
{
struct usb_device *child;
- bool active;
+ bool active = false;
int port1;
+ if (udev->offload_usage)
+ return true;
+
usb_hub_for_each_child(udev, port1, child) {
usb_lock_device(child);
active = usb_offload_check(child);
usb_unlock_device(child);
+
if (active)
- return true;
+ break;
}
- return !!udev->offload_usage;
+ return active;
}
EXPORT_SYMBOL_GPL(usb_offload_check);
+
+/**
+ * usb_offload_set_pm_locked - set the PM lock state of a USB device
+ * @udev: the USB device to modify
+ * @locked: the new lock state
+ *
+ * Setting @locked to true prevents offload_usage from being modified. This
+ * ensures that offload activities cannot be started or stopped during critical
+ * power management transitions, maintaining a stable state for the duration
+ * of the transition.
+ */
+void usb_offload_set_pm_locked(struct usb_device *udev, bool locked)
+{
+ spin_lock(&udev->offload_lock);
+ udev->offload_pm_locked = locked;
+ spin_unlock(&udev->offload_lock);
+}
+EXPORT_SYMBOL_GPL(usb_offload_set_pm_locked);