[PATCH 08/15] ppp: Fix throttling bugs

From: Alan Cox
Date: Mon Jun 22 2009 - 12:45:20 EST


From: Alan Cox <alan@xxxxxxxxxxxxxxx>

The ppp layer goes around calling the unthrottle method from non sleeping
paths. This isn't safe because the unthrottle methods in the tty layer need
to be able to sleep (consider a USB dongle).

Until now this didn't show up because the ppp layer never actually throttled
a port so the unthrottle was always a no-op. Currently it's a mutex taking
path so warnings are spewed if the unthrottle occurs via certain paths.

Fix this by removing the unneccessary unthrottle calls.

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---

drivers/net/ppp_async.c | 1 -
drivers/net/ppp_synctty.c | 1 -
2 files changed, 0 insertions(+), 2 deletions(-)


diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c
index 6de8399..17c116b 100644
--- a/drivers/net/ppp_async.c
+++ b/drivers/net/ppp_async.c
@@ -356,7 +356,6 @@ ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf,
if (!skb_queue_empty(&ap->rqueue))
tasklet_schedule(&ap->tsk);
ap_put(ap);
- tty_unthrottle(tty);
}

static void
diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
index d2fa2db..aa3d39f 100644
--- a/drivers/net/ppp_synctty.c
+++ b/drivers/net/ppp_synctty.c
@@ -397,7 +397,6 @@ ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf,
if (!skb_queue_empty(&ap->rqueue))
tasklet_schedule(&ap->tsk);
sp_put(ap);
- tty_unthrottle(tty);
}

static void

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