From: Bob Copeland <me@bobcopeland.com>
To: Hugh Dickins <hugh@veritas.com>
Cc: ath5k-devel@venema.h4ckr.net, linux-wireless@vger.kernel.org,
Jiri Slaby <jirislaby@gmail.com>
Subject: Re: [ath5k-devel] ath5k_tasklet_rx BUG_ON(bf->skb == NULL)
Date: Sat, 10 Jan 2009 11:47:05 -0500 [thread overview]
Message-ID: <20090110164705.GB10865@hash.localnet> (raw)
In-Reply-To: <Pine.LNX.4.64.0901091400290.925@blonde.anvils>
On Fri, Jan 09, 2009 at 02:10:50PM +0000, Hugh Dickins wrote:
> Good, that should be a lot quicker.
Well I got a lockup doing that, I'll try again later but anyway I see
the bug already, read on if interested. I should have a patch shortly.
ath5k_tasklet_rx creates a new skb for every packet that is handed to
the upper layers, and the buffer is moved to the end of the rxbuf list.
But ath5k_rxbuf_setup fails skb_alloc so the buffer is left in the rxbuf
list with a null skb. Once another 40 packets are processed that buffer
comes up again and triggers the BUG_ON. Disabling the BUG_ON is bad
because we could end up with no available buffers.
The fix would be to create a new skb when we accept a packet, and just
drop the packet if that skb creation fails. Then swap in the new skb
after ieee80211_rx. ath9k already does something like this.
--
Bob Copeland %% www.bobcopeland.com
next prev parent reply other threads:[~2009-01-10 16:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-08 13:49 ath5k_tasklet_rx BUG_ON(bf->skb == NULL) Hugh Dickins
2009-01-08 14:46 ` [ath5k-devel] " Maxim Levitsky
2009-01-08 16:18 ` Hugh Dickins
2009-01-08 17:10 ` Bob Copeland
2009-01-08 17:55 ` Hugh Dickins
2009-01-08 18:41 ` Bob Copeland
2009-01-09 13:41 ` Bob Copeland
2009-01-09 14:10 ` Hugh Dickins
2009-01-10 16:47 ` Bob Copeland [this message]
2009-01-10 20:15 ` Bob Copeland
2009-01-13 15:35 ` Hugh Dickins
2009-01-13 15:56 ` Bob Copeland
2009-01-13 16:40 ` Hugh Dickins
2009-01-13 17:45 ` Luis R. Rodriguez
2009-02-06 13:12 ` Hugh Dickins
2009-02-06 18:37 ` Bob Copeland
2009-02-06 18:44 ` John W. Linville
2009-02-06 19:01 ` Hugh Dickins
2009-02-06 20:58 ` Bob Copeland
2009-02-09 2:30 ` Bob Copeland
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