Messages in this thread | | | Subject | Re: [PATCH] via-rhine: Fix tx_timeout handling | From | Ben Hutchings <> | Date | Sun, 21 Jul 2013 17:18:50 +0100 |
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On Fri, 2013-07-19 at 23:30 +0200, Richard Weinberger wrote: > rhine_reset_task() misses to call netif_stop_queue(), > this can lead to a crash if work is still scheduled while > we're resetting the tx queue. > > Fixes: > [ 93.591707] BUG: unable to handle kernel NULL pointer dereference at 0000004c > [ 93.595514] IP: [<c119d10d>] rhine_napipoll+0x491/0x6e > > Signed-off-by: Richard Weinberger <richard@nod.at> > --- > drivers/net/ethernet/via/via-rhine.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/net/ethernet/via/via-rhine.c b/drivers/net/ethernet/via/via-rhine.c > index b75eb9e..57e1b40 100644 > --- a/drivers/net/ethernet/via/via-rhine.c > +++ b/drivers/net/ethernet/via/via-rhine.c > @@ -1615,6 +1615,7 @@ static void rhine_reset_task(struct work_struct *work) > goto out_unlock; > > napi_disable(&rp->napi); > + netif_stop_queue(dev);
This is not really fixing the bug because there is no synchronisation with the TX scheduler. You can call netif_tx_disable() instead to do that.
(I also think that it is preferable to use netif_device_{detach,attach}() to stop the queue during reconfiguration, as this is independent of TX completions and the watchdog.)
Ben.
> spin_lock_bh(&rp->lock); > > /* clear all descriptors */
-- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.
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