pppoatm: fix missing wakeup in pppoatm_send()

Now that we can return zero from pppoatm_send() for reasons *other* than
the queue being full, that means we can't depend on a subsequent call to
pppoatm_pop() waking the queue, and we might leave it stalled
indefinitely.

Use the ->release_cb() callback to wake the queue after the sock is
unlocked.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>

diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
index 3dce84af5dbe0cea71b5e6c98e19e2dcb791c94d..9fcda8c85e9a1342e310fcfb6e67cd7919413311 100644 (file)
--- a/net/atm/pppoatm.c
+++ b/net/atm/pppoatm.c
@@ -60,6 +60,7 @@ struct pppoatm_vcc {
        struct atm_vcc  *atmvcc;        /* VCC descriptor */
        void (*old_push)(struct atm_vcc *, struct sk_buff *);
        void (*old_pop)(struct atm_vcc *, struct sk_buff *);
+       void (*old_release_cb)(struct atm_vcc *);
        struct module *old_owner;
                                        /* keep old push/pop for detaching */
        enum pppoatm_encaps encaps;
@@ -108,6 +109,14 @@ static void pppoatm_wakeup_sender(unsigned long arg)
        ppp_output_wakeup((struct ppp_channel *) arg);
 }
 
+static void pppoatm_release_cb(struct atm_vcc *atmvcc)
+{
+       struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+
+       tasklet_schedule(&pvcc->wakeup_tasklet);
+       if (pvcc->old_release_cb)
+               pvcc->old_release_cb(atmvcc);
+}
 /*
  * This gets called every time the ATM card has finished sending our
  * skb.  The ->old_pop will take care up normal atm flow control,
@@ -152,6 +161,7 @@ static void pppoatm_unassign_vcc(struct atm_vcc *atmvcc)
        pvcc = atmvcc_to_pvcc(atmvcc);
        atmvcc->push = pvcc->old_push;
        atmvcc->pop = pvcc->old_pop;
+       atmvcc->release_cb = pvcc->old_release_cb;
        tasklet_kill(&pvcc->wakeup_tasklet);
        ppp_unregister_channel(&pvcc->chan);
        atmvcc->user_back = NULL;
@@ -388,6 +398,7 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
        pvcc->old_push = atmvcc->push;
        pvcc->old_pop = atmvcc->pop;
        pvcc->old_owner = atmvcc->owner;
+       pvcc->old_release_cb = atmvcc->release_cb;
        pvcc->encaps = (enum pppoatm_encaps) be.encaps;
        pvcc->chan.private = pvcc;
        pvcc->chan.ops = &pppoatm_ops;
@@ -403,6 +414,7 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
        atmvcc->user_back = pvcc;
        atmvcc->push = pppoatm_push;
        atmvcc->pop = pppoatm_pop;
+       atmvcc->release_cb = pppoatm_release_cb;
        __module_get(THIS_MODULE);
        atmvcc->owner = THIS_MODULE;