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>

2 files changed, 21 insertions, 0 deletions

diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c
index 434d5af8e6fb..c81e278629ff 100644
--- 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 fc9f578a1e25..f9819d10b1f9 100644
--- 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);
 
 /*-------------------------------------------------------------------------*/