usbnet: Support devices reporting idleness

Some device types support a form of power management in which
the device suggests to the host that the device may be suspended
now. Support for that is best located in usbnet.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c
index 434d5af..c81e278 100644 (file)
--- a/drivers/net/usb/cdc_eem.c
+++ b/drivers/net/usb/cdc_eem.c
@@ -244,8 +244,12 @@ static int eem_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
                         *  - suspend: peripheral ready to suspend
                         *  - response: suggest N millisec polling
                         *  - response complete: suggest N sec polling
+                        *
+                        * Suspend is reported and maybe heeded.
                         */
                        case 2:         /* Suspend hint */
+                               usbnet_device_suggests_idle(dev);
+                               continue;
                        case 3:         /* Response hint */
                        case 4:         /* Response complete hint */
                                continue;

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index fc9f578..f9819d1 100644 (file)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1588,10 +1588,27 @@ int usbnet_resume (struct usb_interface *intf)
                        tasklet_schedule (&dev->bh);
                }
        }
+
+       if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
+               usb_autopm_get_interface_no_resume(intf);
+
        return 0;
 }
 EXPORT_SYMBOL_GPL(usbnet_resume);
 
+/*
+ * Either a subdriver implements manage_power, then it is assumed to always
+ * be ready to be suspended or it reports the readiness to be suspended
+ * explicitly
+ */
+void usbnet_device_suggests_idle(struct usbnet *dev)
+{
+       if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
+               dev->intf->needs_remote_wakeup = 1;
+               usb_autopm_put_interface_async(dev->intf);
+       }
+}
+EXPORT_SYMBOL(usbnet_device_suggests_idle);
 
 /*-------------------------------------------------------------------------*/
 

diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index f87cf62..ddbbb7d 100644 (file)
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -68,6 +68,7 @@ struct usbnet {
 #              define EVENT_RX_PAUSED  5
 #              define EVENT_DEV_ASLEEP 6
 #              define EVENT_DEV_OPEN   7
+#              define EVENT_DEVICE_REPORT_IDLE 8
 };
 
 static inline struct usb_driver *driver_of(struct usb_interface *intf)
@@ -160,6 +161,7 @@ extern int usbnet_probe(struct usb_interface *, const struct usb_device_id *);
 extern int usbnet_suspend(struct usb_interface *, pm_message_t);
 extern int usbnet_resume(struct usb_interface *);
 extern void usbnet_disconnect(struct usb_interface *);
+extern void usbnet_device_suggests_idle(struct usbnet *dev);
 
 
 /* Drivers that reuse some of the standard USB CDC infrastructure