#2621 BLOC Trial-3: wireless suspend/resume failure under high-traffic

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#2621: wireless suspend/resume failure under high-traffic
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  Reporter:  marcelo   |       Owner:  rchokshi
      Type:  defect    |      Status:  new     
  Priority:  blocker   |   Milestone:  Trial-3 
 Component:  wireless  |     Version:          
Resolution:            |    Keywords:          
  Verified:  0         |  
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Changes (by rchokshi):

 * cc: GR-Wireless-OLPC at marvell.com, javier at cozybit.com (added)

Comment:

 Clarification from Marcelo:

 {{{
 On suspend we:

 1) stop all incoming/outcomming traffic on the network device
 2) stop all pending URB's (waiting for the ones in progress to finish)

 The failure on resume happens after the USB probe has been done,
 whenever we try to communicate to the device on endpoint 2.

 Luis confirmed that the firmware will not try to send any packets to the
 host before it receives some data on endpoint 2, meaning that we don't
 suffer from the problem where the firmware sends data before the USB
 links are fully established (network traffic is dropped in this case).

 The host will only try to send packets after resume is done. The problem
 happens _before_ that:

 static int if_usb_resume(struct usb_interface *intf)
 {
         struct usb_card_rec *cardp = usb_get_intfdata(intf);
         wlan_private *priv = cardp->priv;

         lbs_deb_enter(LBS_DEB_USB);

         cardp->rx_urb_recall = 0;

         if_usb_submit_rx_urb(cardp->priv);

         reestablish_connection(priv);    <------- HERE
         reestablish_connection(priv);
         reestablish_connection(priv);

         netif_device_attach(cardp->eth_dev);
         netif_device_attach(priv->mesh_dev);
 }}}

-- 
Ticket URL: <https://dev.laptop.org/ticket/2621#comment:2>
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