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From: Felix Fietkau <>
To: "Luis R. Rodriguez" <>
	Jouni Malinen <>
Subject: Re: [PATCH 2/3] ath9k_hw: clean up per-channel calibration data
Date: Wed, 28 Jul 2010 23:10:57 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 2010-07-28 10:52 PM, Luis R. Rodriguez wrote:
> On Wed, Jul 28, 2010 at 10:45 AM, Felix Fietkau <> wrote:
>> The noise floor history buffer is currently not kept per channel, which
>> can lead to problems when changing channels from a clean channel to a
>> noisy one. Also when switching from HT20 to HT40, the noise floor
>> history buffer is full of measurements, but none of them contain data
>> for the extension channel, which it needs quite a bit of time to recover
>> from.
>> This patch puts all the per-channel calibration data into a single data
>> structure, and gives the the driver control over whether that is used
>> per-channel or even not used for some channels.
>> For ath9k_htc, I decided to keep this per-channel in order to avoid
>> creating regressions.
>> For ath9k, the data is kept only for the operating channel, which saves
>> some space. ath9k_hw takes care of wiping old data when the operating
>> channel or its channel flags change.
>> Signed-off-by: Felix Fietkau <>
> But this also means every time we want to get operational on a channel
> we have to learn the current noise all over again. This means for WiFi
> Direct every channel swap we'd have to learn to walk, which happens
> quite often. What do you think? Sorry, I know we discussed this
> approach and I seemed fine but this just occurred to me now, and will
> become really important later when we support WiFi Direct.
When we get to implementing per-vif channel settings with switching
being done in mac80211, we can just move the calibration data to ath9k's
virtual interface data and thus keep the calibration for multiple
operating channels.

- Felix

  reply	other threads:[~2010-07-28 21:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-28 17:45 [PATCH 1/3] ath9k: prevent calibration during off-channel activity Felix Fietkau
2010-07-28 17:45 ` [PATCH 2/3] ath9k_hw: clean up per-channel calibration data Felix Fietkau
2010-07-28 17:45   ` [PATCH 3/3] ath9k_hw: fix a noise floor calibration related race condition Felix Fietkau
2010-07-28 20:52   ` [PATCH 2/3] ath9k_hw: clean up per-channel calibration data Luis R. Rodriguez
2010-07-28 21:10     ` Felix Fietkau [this message]
2010-07-28 21:21       ` Luis R. Rodriguez
2010-07-28 21:30         ` Felix Fietkau
2010-07-28 21:40           ` Luis R. Rodriguez
2010-07-28 22:03             ` Felix Fietkau
2010-07-28 20:43 ` [PATCH 1/3] ath9k: prevent calibration during off-channel activity Luis R. Rodriguez
2010-07-28 21:08   ` Felix Fietkau
2010-07-28 22:12     ` Luis R. Rodriguez
2010-07-28 22:28       ` Felix Fietkau
2010-07-28 22:47         ` Luis R. Rodriguez
2010-07-28 22:48           ` Luis R. Rodriguez
2010-07-29 16:58             ` wireless-next-2.6 rebase -- " John W. Linville

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