usb: hub: delay hub autosuspend if USB3 port is still link training
authorMathias Nyman <mathias.nyman@linux.intel.com>
Wed, 28 Nov 2018 13:55:21 +0000 (15:55 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 5 Dec 2018 09:12:31 +0000 (10:12 +0100)
When initializing a hub we want to give a USB3 port in link training
the same debounce delay time before autosuspening the hub as already
trained, connected enabled ports.

USB3 ports won't reach the enabled state with "current connect status" and
"connect status change" bits set until the USB3 link training finishes.

Catching the port in link training (polling) and adding the debounce delay
prevents unnecessary failed attempts to autosuspend the hub.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hub.c

index 0f9381b69a3b563bc63d8010a639bb270f0fc2c8..009f92800e0378efeeb320ea6905f0fb1327e806 100644 (file)
@@ -1112,6 +1112,16 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
                                                   USB_PORT_FEAT_ENABLE);
                }
 
+               /*
+                * Add debounce if USB3 link is in polling/link training state.
+                * Link will automatically transition to Enabled state after
+                * link training completes.
+                */
+               if (hub_is_superspeed(hdev) &&
+                   ((portstatus & USB_PORT_STAT_LINK_STATE) ==
+                                               USB_SS_PORT_LS_POLLING))
+                       need_debounce_delay = true;
+
                /* Clear status-change flags; we'll debounce later */
                if (portchange & USB_PORT_STAT_C_CONNECTION) {
                        need_debounce_delay = true;