[PATCH 3.13.y-ckt 41/43] cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind

From: Kamal Mostafa
Date: Tue Mar 22 2016 - 17:07:50 EST


3.13.11-ckt37 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@xxxxxxx>

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@xxxxxxxxx>
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: BjÃrn Mork <bjorn@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[ luis: backported to 3.16:
- cdc_ncm_bind_common() takes only 3 args in 3.16
- adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
[ kamal: bakcported to 3.13: context ]
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/net/usb/cdc_ncm.c | 21 +++++----------------
1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index f2c3646..7fc1278 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -561,24 +561,12 @@ 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? */
cdc_ncm_select_altsetting(dev, intf);
if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
return -ENODEV;

- /* NCM data altsetting is always 1 */
- ret = cdc_ncm_bind_common(dev, intf, 1);
-
- /*
- * 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, 1);
}

static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
@@ -1107,7 +1095,8 @@ static int cdc_ncm_check_connect(struct usbnet *dev)

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,
.check_connect = cdc_ncm_check_connect,
@@ -1121,7 +1110,7 @@ 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,
.check_connect = cdc_ncm_check_connect,
@@ -1135,7 +1124,7 @@ 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,
.check_connect = cdc_ncm_check_connect,
--
2.7.0