Ideally, usbnet_resume is sufficient for device resume operation.
since usbcore function usb_resume_device() sets udev->reset_resume
flag as a quirk solution, reset_resume() quirk we can keep in
class driver also. We checked on dongle DA-Queen UFE20C,
without reset function resume operation fails. Reason could be
some power glitch during suspend time due to which device lose
its internal state and it needs a device phy reset again during
resume to recover.

Signed-off-by: Vivek Kumar Bhagat <[email protected]>
Signed-off-by: Vikas Bansal <[email protected]>
Signed-off-by: Sangmin Bae <[email protected]>
---
 drivers/net/usb/asix_devices.c |    1 +
 drivers/net/usb/cdc_eem.c      |    1 +
 drivers/net/usb/usbnet.c       |   17 +++++++++++++++++
 include/linux/usb/usbnet.h     |    1 +
 4 files changed, 20 insertions(+)

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 5cabefc..68dda61 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -1097,6 +1097,7 @@ static struct usb_driver asix_driver = {
        .probe =        usbnet_probe,
        .suspend =      usbnet_suspend,
        .resume =       usbnet_resume,
+       .reset_resume = usbnet_reset_resume,
        .disconnect =   usbnet_disconnect,
        .supports_autosuspend = 1,
        .disable_hub_initiated_lpm = 1,
diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c
index f7180f8..83b6857 100644
--- a/drivers/net/usb/cdc_eem.c
+++ b/drivers/net/usb/cdc_eem.c
@@ -371,6 +371,7 @@ static struct usb_driver eem_driver = {
        .disconnect =   usbnet_disconnect,
        .suspend =      usbnet_suspend,
        .resume =       usbnet_resume,
+       .reset_resume = usbnet_reset_resume,
        .disable_hub_initiated_lpm = 1,
 };
 
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 61ba464..f56c176 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1876,6 +1876,23 @@ int usbnet_resume (struct usb_interface *intf)
 }
 EXPORT_SYMBOL_GPL(usbnet_resume);
 
+int usbnet_reset_resume(struct usb_interface *intf)
+{
+       struct usbnet *dev = usb_get_intfdata(intf);
+       int ret;
+
+       if (dev->driver_info->reset) {
+               ret = dev->driver_info->reset(dev);
+               if (ret < 0)
+                       return ret;
+
+               return usbnet_resume(intf);
+       }
+
+       return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(usbnet_reset_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
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index 6e0ce8c..0b261d5 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -177,6 +177,7 @@ struct driver_info {
 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 int usbnet_reset_resume(struct usb_interface *);
 extern void usbnet_disconnect(struct usb_interface *);
 extern void usbnet_device_suggests_idle(struct usbnet *dev);
 
-- 
1.7.9.5

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