From: Felix Fietkau <nbd@openwrt.org>
To: Rostislav Lisovy <lisovy@gmail.com>,
Johannes Berg <johannes@sipsolutions.net>
Cc: "John W. Linville" <linville@tuxdriver.com>,
linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
Michal Sojka <sojkam1@fel.cvut.cz>,
s.sander@nordsys.de, jan-niklas.meier@volkswagen.de,
Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
Subject: Re: [PATCH 2/2] cfg80211: Use 5MHz bandwidth by default when checking usable channels
Date: Mon, 23 Jun 2014 16:46:57 +0200 [thread overview]
Message-ID: <53A83DE1.4050106@openwrt.org> (raw)
In-Reply-To: <1403534300.7341.6.camel@lolumad>
On 2014-06-23 16:38, Rostislav Lisovy wrote:
> On Mon, 2014-06-23 at 12:05 +0200, Johannes Berg wrote:
>> On Mon, 2014-06-23 at 12:04 +0200, Felix Fietkau wrote:
>> > On 2014-06-23 11:08, Johannes Berg wrote:
>> > > On Sun, 2014-06-22 at 13:41 +0200, Felix Fietkau wrote:
>> > >> On 2014-04-15 14:37, Rostislav Lisovy wrote:
>> > >> > Current code checks if the 20MHz bandwidth is allowed for
>> > >> > particular channel -- if it is not, the channel is disabled.
>> > >> > Since we need to use 5/10 MHz channels, this code is modified in
>> > >> > the way that the default bandwidth to check is 5MHz. If the
>> > >> > maximum bandwidth allowed by the channel is smaller than 5MHz,
>> > >> > the channel is disabled. Otherwise the channel is used and the
>> > >> > flags are set according to the bandwidth allowed by the channel.
>> > >> >
>> > >> > Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
>> > >
>> > >> This change causes a regression and needs to be reverted or fixed.
>> > >
>> > > Noted, I've reverted it in mac80211.git.
>> > >
>> > >> It leaves Channel 12 enabled for US regdomain and does not prevent
>> > >> bringing up AP mode on it (IEEE80211_CHAN_NO_20MHZ does not get set).
>> > >
>> > > I'm not sure this makes sense - CHAN_NO_20MHZ shouldn't get set on that
>> > > channel? It should be disabled for other reasons for AP mode - e.g.
>> > > NO_IR.
>> > I was thinking it could be valid in AP mode for 5 MHz operation.
>>
>> Huh, ok, maybe. I guess Rostislav can look into the details :)
>>
>
> I am a bit confused right now. The regression is that the channel used
> to be completely disabled and now it is not? The regulatory restrictions
> prohibit the 20MHz BW for this channel but 5MHz BW is alright?
Correct. The matching rule is this:
(2402 - 2472 @ 40), (N/A, 30), (N/A)
Channel 11 (2462 MHz) is allowed, because 2472 MHz is below the limit.
Channel 12 (2467 MHz) is not allowed, because 2477 MHz is too high.
With your change, Channel 12 was enabled and usable for AP mode.
- Felix
next prev parent reply other threads:[~2014-06-23 14:47 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-15 12:37 [PATCH 0/2 v3] cfg80211: The very first steps to support 5/10MHz channels in 5.9Ghz band Rostislav Lisovy
2014-04-15 12:37 ` [PATCH 1/2] cfg80211: Add attributes describing prohibited channel bandwidth Rostislav Lisovy
2014-04-15 12:37 ` [PATCH 2/2] cfg80211: Use 5MHz bandwidth by default when checking usable channels Rostislav Lisovy
2014-06-22 11:41 ` Felix Fietkau
2014-06-23 9:08 ` Johannes Berg
2014-06-23 10:04 ` Felix Fietkau
2014-06-23 10:05 ` Johannes Berg
2014-06-23 14:38 ` Rostislav Lisovy
2014-06-23 14:46 ` Felix Fietkau [this message]
2014-06-23 14:58 ` Rostislav Lisovy
2014-04-25 15:40 ` [PATCH 0/2 v3] cfg80211: The very first steps to support 5/10MHz channels in 5.9Ghz band Johannes Berg
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