From: Yueyao Zhu <yue...@google.com>
An interface driver can allow/disallow autosuspend power control
for an interface, and if all the interfaces of the active configuration
are allowed for autosuspend, autosuspend should be enabled
on the usb device.
Signed-off-by: Yueyao Zhu <yue...@google.com>
---
drivers/usb/core/driver.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/usb.h | 10 +++++++++
2 files changed, 65 insertions(+)
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index eb87a259d55c..c0a20f03ad01 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1545,6 +1545,61 @@ void usb_disable_autosuspend(struct usb_device *udev)
}
EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
+/**
+ * usb_allow_interface_autosuspend - allow autosuspend for the interface
+ * @intf: the USB interface which may be autosuspended
+ *
+ * This routine votes the interface to allow autosuspend. If all interfaces
+ * of the active configuration of the usb device allow autosuspend, autosuspend
+ * is enabled on the usb device through usb_enable_autosuspend().
+ *
+ * The only interface driver that will enable autosuspend on the
+ * USB device is the last in loop during interface driver probe, or midway
+ * through life if an interface changes its autosuspend status, and all other
+ * interfaces have already said yes.
+ *
+ * The caller must hold @udev's device lock.
+ */
+void usb_allow_interface_autosuspend(struct usb_interface *intf)
+{
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct usb_host_config *actconfig = udev->actconfig;
+ int i;
+ bool udev_autosuspend = true;
+
+ intf->autosuspend = 1;
+
+ for (i = 0; i < actconfig->desc.bNumInterfaces; ++i) {
+ if (!actconfig->interface[i]->autosuspend) {
+ udev_autosuspend = false;
+ break;
+ }
+ }
+
+ if (udev_autosuspend)
+ usb_enable_autosuspend(udev);
+}
+EXPORT_SYMBOL_GPL(usb_allow_interface_autosuspend);
+
+/**
+ * usb_disallow_interface_autosuspend - disallow autosuspend for the interface
+ * @intf: the USB interface which may not be autosuspended
+ *
+ * This routine votes the interface to disallow autosuspend. This immediately
+ * disables autosuspend on the usb device through usb_enable_autosuspend().
+ *
+ * The caller must hold @udev's device lock.
+ */
+void usb_disallow_interface_autosuspend(struct usb_interface *intf)
+{
+ struct usb_device *udev = interface_to_usbdev(intf);
+
+ intf->autosuspend = 0;
+
+ usb_disable_autosuspend(udev);
+}
+EXPORT_SYMBOL_GPL(usb_disallow_interface_autosuspend);
+
/**
* usb_autosuspend_device - delayed autosuspend of a USB device and its
interfaces
* @udev: the usb_device to autosuspend
diff --git a/include/linux/usb.h b/include/linux/usb.h
index cb9fbd54386e..723ab9130637 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -253,6 +253,7 @@ struct usb_interface {
unsigned needs_binding:1; /* needs delayed unbind/rebind */
unsigned resetting_device:1; /* true: bandwidth alloc after reset */
unsigned authorized:1; /* used for interface authorization */
+ unsigned autosuspend:1; /* interface allows autosuspend */
struct device dev; /* interface specific device info */
struct device *usb_dev;
@@ -741,6 +742,9 @@ static inline bool usb_acpi_power_manageable(struct
usb_device *hdev, int index)
extern void usb_enable_autosuspend(struct usb_device *udev);
extern void usb_disable_autosuspend(struct usb_device *udev);
+extern void usb_allow_interface_autosuspend(struct usb_interface *intf);
+extern void usb_disallow_interface_autosuspend(struct usb_interface *intf);
+
extern int usb_autopm_get_interface(struct usb_interface *intf);
extern void usb_autopm_put_interface(struct usb_interface *intf);
extern int usb_autopm_get_interface_async(struct usb_interface *intf);
@@ -760,6 +764,12 @@ static inline int usb_enable_autosuspend(struct usb_device
*udev)
static inline int usb_disable_autosuspend(struct usb_device *udev)
{ return 0; }
+static inline void usb_allow_interface_autosuspend(struct usb_interface *intf)
+{ }
+static inline void usb_disallow_interface_autosuspend(
+ struct usb_interface *intf)
+{ }
+
static inline int usb_autopm_get_interface(struct usb_interface *intf)
{ return 0; }
static inline int usb_autopm_get_interface_async(struct usb_interface *intf)
--
2.13.0.506.g27d5fe0cd-goog
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