From: Adrian Chadd <adrian@freebsd.org>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Rajkumar Manoharan <rmanoharan@atheros.com>,
linville@tuxdriver.com, linux-wireless@vger.kernel.org
Subject: Re: [PATCH 6/6] mac80211: stop queues before rate control updation
Date: Tue, 31 May 2011 15:20:50 +0800 [thread overview]
Message-ID: <BANLkTimotXTy3Lk8CH6LZ3KD=f9iWOtJmw@mail.gmail.com> (raw)
In-Reply-To: <1306823717.9366.3.camel@jlt3.sipsolutions.net>
On 31 May 2011 14:35, Johannes Berg <johannes@sipsolutions.net> wrote:
> Looks like I completely missed this since you hid it in an ath9k
> patchset. DON'T DO THAT.
>
> Anyway, John, please revert. This is completely useless. Not only is
> abusing the CSA stop reason a show-stopper, the whole patch is also just
> not right, it seems like a workaround around a rate control algorithm
> that isn't able to do an atomic HT change by itself. Also, it won't even
> do what you want, there may be packets being processed concurrently
> while stopping the queue -- calling stop_queues() is no guarantee that
> no packet will be processed afterwards.
I'm unsure of what's going on in mac80211 and ath9k here.
FreeBSD handles it very simply - it goes via ath_reset() which drains
each TX queue, freeing existing packets. Inefficient (ie, packet loss)
but fine for now.
How is ath9k handling the situation where the hardware currently has
HT40 packets queued in the TX queues and you do a 40->20 change?
The 40->20 change in the ath9k instance requires reinit'ing of the
card. What happens to currently queued packets?
Adrian
next prev parent reply other threads:[~2011-05-31 7:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-20 12:22 [PATCH 1/6] ath9k: Reset chip on baseband hang Rajkumar Manoharan
2011-05-20 12:22 ` [PATCH 3/6] ath9k: Handle IBSS status changes in BSS_CHANGED_IBSS Rajkumar Manoharan
2011-05-20 12:22 ` [PATCH 4/6] ath9k_hw: disable phy restart on baseband panic caused by RXSM Rajkumar Manoharan
2011-05-20 12:22 ` [PATCH 5/6] ath9k: set 40 Mhz rate only if hw is configured in ht40 Rajkumar Manoharan
2011-05-20 12:22 ` [PATCH 6/6] mac80211: stop queues before rate control updation Rajkumar Manoharan
2011-05-31 6:35 ` Johannes Berg
2011-05-31 7:20 ` Adrian Chadd [this message]
2011-06-01 18:58 ` John W. Linville
2011-06-03 5:00 ` Manoharan, Rajkumar
2011-06-06 18:44 ` John W. Linville
2011-06-06 18:57 ` Johannes Berg
2011-06-07 8:39 ` Manoharan, Rajkumar
2011-06-07 18:05 ` John W. Linville
[not found] ` <1305894135-14036-2-git-send-email-rmanoharan@atheros.com>
2011-05-21 4:27 ` [PATCH 2/6] ath9k: Remove ATH9K_BEACON_PERIOD mask Rajkumar Manoharan
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