UPSTREAM: USB: Handle auto-transition from hot to warm reset.

commit 1c7439c61fa6516419c32a9824976334ea969d47 upstream.

USB 3.0 hubs and roothubs will automatically transition a failed hot
reset to a warm (BH) reset.  In that case, the warm reset change bit
will be set, and the link state change bit may also be set.  Change
hub_port_finish_reset to unconditionally clear those change bits for USB
3.0 hubs.  If these bits are not cleared, we may lose port change events
from the roothub.

This commit should be backported to kernels as old as 3.2, that contain
the commit 75d7cf72ab9fa01dc70877aa5c68e8ef477229dc "usbcore: refine
warm reset logic".

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 98e5587b9abe155e356d9eef3be6b1472c508c96)

BUG=None
TEST=Together with other cherry-picks: run BVT trybots on all platforms,
manually confirm that USB network/storage/input devices still work
(including across suspend/resume)

Change-Id: I6ad1fa529a0e4a30a881dd2a07f4958f5947835c
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/46066
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 79655ee..41ec20b 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2240,16 +2240,16 @@ static void hub_port_finish_reset(struct usb_hub *hub, int port1,
                clear_port_feature(hub->hdev,
                                port1, USB_PORT_FEAT_C_RESET);
                /* FIXME need disconnect() for NOTATTACHED device */
-               if (warm) {
+               if (hub_is_superspeed(hub->hdev)) {
                        clear_port_feature(hub->hdev, port1,
                                        USB_PORT_FEAT_C_BH_PORT_RESET);
                        clear_port_feature(hub->hdev, port1,
                                        USB_PORT_FEAT_C_PORT_LINK_STATE);
-               } else {
+               }
+               if (!warm)
                        usb_set_device_state(udev, *status
                                        ? USB_STATE_NOTATTACHED
                                        : USB_STATE_DEFAULT);
-               }
                break;
        }
 }