[RFC PATCH v2 6/6] usb: add usb port's pm qos flags request to change NO_POWER_OFF flag

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Some usb devices can't be resumed correctly after power off. This
patch is to add pm qos flags request to change NO_POWER_OFF and
provide usb_device_allow_power_off() for device drivers to allow or
prohibit usb core to power off the device.

Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
 drivers/usb/core/hub.c  |   36 ++++++++++++++++++++++++++++++++++++
 drivers/usb/core/port.c |   12 ++++++++++++
 include/linux/usb.h     |    3 +++
 3 files changed, 51 insertions(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 267e9d7..7aaac720 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -189,6 +189,42 @@ static struct usb_hub *hdev_to_hub(struct usb_device *hdev)
 	return usb_get_intfdata(hdev->actconfig->interface[0]);
 }
 
+/**
+ * usb_device_allow_power_off - Allow or prohibit power off device.
+ * @udev: target usb device
+ * @set: choice of allow or prohibit
+ *
+ * Clearing or setting usb port's pm qos flag PM_QOS_FLAG_NO_POWER_OFF
+ * to allow or prohibit target usb device to be power off.
+ */
+int usb_device_allow_power_off(struct usb_device *udev, bool set)
+{
+	struct usb_port *port_dev;
+	struct dev_pm_qos_request *pm_qos;
+	s32 value;
+	int ret;
+
+	if (!udev->parent)
+		return -EINVAL;
+
+	port_dev =
+		hdev_to_hub(udev->parent)->ports[udev->portnum - 1];
+	pm_qos = &port_dev->pm_qos;
+	value = pm_qos->data.flr.flags;
+
+	if (set)
+		value &= ~PM_QOS_FLAG_NO_POWER_OFF;
+	else
+		value |= PM_QOS_FLAG_NO_POWER_OFF;
+
+	pm_runtime_get_sync(&port_dev->dev);
+	ret = dev_pm_qos_update_request(pm_qos, value);
+	pm_runtime_put(&port_dev->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usb_device_allow_power_off);
+
 static int usb_device_supports_lpm(struct usb_device *udev)
 {
 	/* USB 2.1 (and greater) devices indicate LPM support through
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 5a7a833..077a494 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -49,6 +49,11 @@ static const struct attribute_group *port_dev_group[] = {
 static void usb_port_device_release(struct device *dev)
 {
 	struct usb_port *port_dev = to_usb_port(dev);
+
+	pm_runtime_get_sync(dev);
+	dev_pm_qos_remove_request(&port_dev->pm_qos);
+	pm_runtime_put(dev);
+
 	dev_pm_qos_hide_flags(dev);
 	usb_acpi_unregister_power_resources(dev);
 	kfree(port_dev);
@@ -116,12 +121,19 @@ int usb_hub_create_port_device(struct device *intfdev,
 	if (retval)
 		goto error_expose_pm_qos;
 
+	retval = dev_pm_qos_add_request(&port_dev->dev, &port_dev->pm_qos,
+			DEV_PM_QOS_FLAGS, 0);
+	if (retval)
+		goto error_add_qos_request;
+
 	pm_runtime_set_active(&port_dev->dev);
 	pm_runtime_enable(&port_dev->dev);
 	usb_acpi_register_power_resources(&port_dev->dev);
 
 	return 0;
 
+error_add_qos_request:
+	pm_runtime_put(&port_dev->dev);
 error_expose_pm_qos:
 	device_del(&port_dev->dev);
 error_register:
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 8002640..aa201bd 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -21,6 +21,7 @@
 #include <linux/sched.h>	/* for current && schedule_timeout */
 #include <linux/mutex.h>	/* for struct mutex */
 #include <linux/pm_runtime.h>	/* for runtime PM */
+#include <linux/pm_qos.h>	/* for PM Qos */
 
 struct usb_device;
 struct usb_driver;
@@ -577,6 +578,7 @@ struct usb_device {
  * @child: usb device attatched to the port
  * @dev: generic device interface
  * @port_owner: port's owner
+ * @pm_qos: port's pm qos flags request
  * @connect_type: port's connect type
  * @portnum: port index num based one
  * @power_on: port's power state
@@ -585,6 +587,7 @@ struct usb_port {
 	struct usb_device *child;
 	struct device dev;
 	struct dev_state *port_owner;
+	struct dev_pm_qos_request pm_qos;
 	enum usb_port_connect_type connect_type;
 	u8 portnum;
 	bool power_on;
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux