[PATCH 4.2.y-ckt 95/98] cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind

Kamal Mostafa
2016-03-15T23:31:29Z

From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>

commit 4d06dd537f95683aba3651098ae288b7cbff8274 upstream.

usbnet_link_change will call schedule_work and should be
avoided if bind is failing. Otherwise we will end up with
scheduled work referring to a netdev which has gone away.

Instead of making the call conditional, we can just defer
it to usbnet_probe, using the driver_info flag made for
this purpose.

Fixes: 8a34b0ae8778 ("usbnet: cdc_ncm: apply usbnet_link_change")
Reported-by: Andrey Konovalov <andreyknvl@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/net/usb/cdc_ncm.c | 20 +++++---------------
1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index e278a7a..f49d684f 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -992,8 +992,6 @@ EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);

static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
{
- int ret;
-
/* MBIM backwards compatible function? */
if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
return -ENODEV;
@@ -1002,16 +1000,7 @@ static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
* Additionally, generic NCM devices are assumed to accept arbitrarily
* placed NDP.
*/
- ret = cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
-
- /*
- * We should get an event when network connection is "connected" or
- * "disconnected". Set network connection in "disconnected" state
- * (carrier is OFF) during attach, so the IP network stack does not
- * start IPv6 negotiation and more.
- */
- usbnet_link_change(dev, 0, 0);
- return ret;
+ return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
}

static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
@@ -1594,7 +1583,8 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)

static const struct driver_info cdc_ncm_info = {
.description = "CDC NCM",
- .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
+ .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
+ | FLAG_LINK_INTR,
.bind = cdc_ncm_bind,
.unbind = cdc_ncm_unbind,
.manage_power = usbnet_manage_power,
@@ -1607,7 +1597,7 @@ static const struct driver_info cdc_ncm_info = {
static const struct driver_info wwan_info = {
.description = "Mobile Broadband Network Device",
.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
- | FLAG_WWAN,
+ | FLAG_LINK_INTR | FLAG_WWAN,
.bind = cdc_ncm_bind,
.unbind = cdc_ncm_unbind,
.manage_power = usbnet_manage_power,
@@ -1620,7 +1610,7 @@ static const struct driver_info wwan_info = {
static const struct driver_info wwan_noarp_info = {
.description = "Mobile Broadband Network Device (NO ARP)",
.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
- | FLAG_WWAN | FLAG_NOARP,
+ | FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
.bind = cdc_ncm_bind,
.unbind = cdc_ncm_unbind,
.manage_power = usbnet_manage_power,
--
2.7.0