Re: regdomain
From: Luis R. Rodriguez <hidden>
Date: 2011-03-29 18:06:35
On Mon, Mar 28, 2011 at 10:09 PM, James [off-list ref] wrote:
I am in Canada so is 0x10 right?
Nope, CA has these two mappings:
{CTRY_CANADA, FCC3_FCCA, "CA"},
{CTRY_CANADA2, FCC6_FCCA, "CA"},
Is there a tool I can use to read the EEPROM?
The ath driver spits it out for you:
ath: EEPROM regdomain: 0x10
That's it.
ath: EEPROM indicates we should expect a direct regpair map ath: Country alpha2 being used: CO ath: Regpair used: 0x10
Sorry for the confusion, 0x10 is a value that is used for a few
countries, specifically, 0x10 maps to a name "FCC1_FCCA" and all these
countries map to 0x10:
mcgrof@tux ~/wireless-testing (git::master)$ grep FCC1_FCCA
drivers/net/wireless/ath/regd_common.h
FCC1_FCCA = 0x10,
{FCC1_FCCA, CTL_FCC, CTL_FCC},
{CTRY_DEFAULT, FCC1_FCCA, "CO"},
{CTRY_COLOMBIA, FCC1_FCCA, "CO"},
{CTRY_DOMINICAN_REPUBLIC, FCC1_FCCA, "DO"},
{CTRY_GUAM, FCC1_FCCA, "GU"},
{CTRY_GUATEMALA, FCC1_FCCA, "GT"},
{CTRY_MEXICO, FCC1_FCCA, "MX"},
{CTRY_PANAMA, FCC1_FCCA, "PA"},
{CTRY_PUERTO_RICO, FCC1_FCCA, "PR"},
In reality that print, " ath: Country alpha2 being used: CO" should
say something like this:
ath: Country alpha2 which can be used: CO, DO, GU, GT, MX, PA, PR
But the Canada regulatory domain is indeed not being used. The differences:
country CA:
(2402 - 2472 @ 40), (3, 27)
(5170 - 5250 @ 40), (3, 17)
(5250 - 5330 @ 40), (3, 20), DFS
(5490 - 5710 @ 40), (3, 20), DFS
(5735 - 5835 @ 40), (3, 30)
country US:
(2402 - 2472 @ 40), (3, 27)
(5170 - 5250 @ 40), (3, 17)
(5250 - 5330 @ 40), (3, 20), DFS
(5490 - 5600 @ 40), (3, 20), DFS
(5650 - 5710 @ 40), (3, 20), DFS
(5735 - 5835 @ 40), (3, 30)
In the US 5600-5650 was removed due to this commit:
Author: Luis R. Rodriguez [off-list ref]
Date: Thu Nov 5 12:46:25 2009 -0500
wireless-regdb: update US rules for 5600 MHz - 5650 MHz
The FCC is trying to assist airports that use Terminal Doppler
Weather Radar (TDWR) systems in avoiding interference with
some outdoor wireless systems operating in the 5.4 GHz
(5470 MHz - 5725 MHz) band. One of the things they have decided
on is to disallow operation on the 5600 MHz - 5650 MHz frequency
range inclusive. What this means in practice is 5 GHz 802.11
devices programmed to operate in the US will have these
channels now disabled:
* 5600 MHz [120] (disabled)
* 5620 MHz [124] (disabled)
* 5640 MHz [128] (disabled)
Channel on 5660 MHz (132) will be left enabled as the channel
bandwidth is 20 MHz for legacy 802.11 networks but note that
HT40- will be disallowed for that channel. The HT40+ and HT40-
allowed channel map obviously changes. This is computed
dynamically on cfg80211 based on your allowed channel list.
For a US based device this is what you will get now
(excerpt from on /sys/kernel/debug/ieee80211/phy0):
.. etc ..
5540 HT40 -+
5560 HT40 -+
5580 HT40 -
5600 Disabled
5620 Disabled
5640 Disabled
5660 HT40 +
5680 HT40 -+
.. etc ..
The details on which this patch is based on is documented on
the FCC Knowledge based Publication Number: 443999 [1]
[1] https://fjallfoss.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?switch=P&id=41732
Cc: Michael Green [off-list ref]
Cc: Senthil Balasubramanian [off-list ref]
Cc: David Quan [off-list ref]
Cc: Vivek Natarajan [off-list ref]
Signed-off-by: Luis R. Rodriguez [off-list ref]
Signed-off-by: John W. Linville [off-list ref]
So that's all you are missing out on, and I would not be surprised if
CA passed similar rules for their own reguatory domain, but the
important thing is your card remains compliant with CA. Hope this
clarifies things.
Luis