From: Felix Fietkau <nbd@nbd.name>
To: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>,
kvalo@codeaurora.org, helgaas@kernel.org,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
marc.zyngier@arm.com, Janusz.Dziedzic@tieto.com,
rmanohar@qti.qualcomm.com, ath9k-devel@qca.qualcomm.com,
linux-wireless@vger.kernel.org, rmanohar@qca.qualcomm.com,
bharat.kumar.gogada@xilinx.com
Subject: Re: [PATCH] ath9k: unlock rcu read when returning early
Date: Tue, 13 Dec 2016 14:52:49 +0100 [thread overview]
Message-ID: <25aebea3-f954-6bef-f17f-162c9c8b6559@nbd.name> (raw)
In-Reply-To: <7b4b7748-06d6-92d4-228c-e7ebf00f8699@mni.thm.de>
On 2016-12-13 14:41, Tobias Klausmann wrote:
> On 13.12.2016 11:41, Felix Fietkau wrote:
>> On 2016-12-12 19:50, Tobias Klausmann wrote:
>>> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
>>> index 52bfbb988611..857d5ae09a1d 100644
>>> --- a/drivers/net/wireless/ath/ath9k/xmit.c
>>> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
>>> @@ -2787,6 +2787,7 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
>>> fifo_list = &txq->txq_fifo[txq->txq_tailidx];
>>> if (list_empty(fifo_list)) {
>>> ath_txq_unlock(sc, txq);
>>> + rcu_read_unlock();
>> Technically this is fine as well, but I'd prefer a fix where you replace
>> the 'return' with 'break', thus avoiding the duplication of
>> rcu_read_unlock()
>
> Actually if you want to avoid it, maybe skipping over the rest is better
> (as originally intended):
>
> ...
>
> ath_txq_unlock(sc, txq);
>
>
> goto unlock;
> }
> ...
>
> unlock:
> rcu_read_unlock();
There are already other places that skip to the rcu_read_unlock() part
by using 'break'. I don't see how adding an unnecessary goto makes
things any better.
- Felix
next prev parent reply other threads:[~2016-12-13 13:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1cFMHb-00BdWd-Ks>
2016-12-12 18:50 ` [PATCH] ath9k: unlock rcu read when returning early Tobias Klausmann
2016-12-13 9:59 ` Kalle Valo
2016-12-13 10:41 ` Felix Fietkau
2016-12-13 13:41 ` Tobias Klausmann
2016-12-13 13:52 ` Felix Fietkau [this message]
2016-12-13 17:08 ` [PATCH v2] ath9k: do not return early to fix rcu unlocking Tobias Klausmann
2016-12-14 20:45 ` Felix Fietkau
2016-12-21 14:29 ` [v2] " Kalle Valo
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