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Date: Fri, 24 Jun 2011 21:43:57 +0530
Message-ID: <BANLkTikkYuENv4CSNxb_NcT2ga0PqHwR2Q@mail.gmail.com> (sfid-20110624_181403_520459_82D3F47B)
Subject: Re: cfg80211 'iw reg set' no longer works after trying to set invalid
From: Mohammed Shafi <shafi.wireless@gmail.com>
To: Laura Nayman <lnayman@gmail.com>
Cc: linux-wireless@vger.kernel.org,
	"Luis R. Rodriguez" <mcgrof@gmail.com>
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Sender: linux-wireless-owner@vger.kernel.org

On Fri, Jun 24, 2011 at 8:13 PM, Laura Nayman <lnayman@gmail.com> wrote:
> cfg80211 'iw reg set' no longer works after trying to set invalid country
> code
>
> You can change the wireless region by using 'iw set reg'. Normally you can
> switch back and forth just fine...
>
> # iw reg set US
> # iw reg get | grep country
> country US:
> # iw reg set JP
> # iw reg get | grep country
> country JP:
> # iw reg set US
> # iw reg get | grep country
> country US:
>
>
> However, if we try to use an invalid country code, such as XX:
> # iw reg set XX
> # iw reg get | grep country
> country US:
> ... it doesn't take. Okay, no big deal. Let's try setting it back to JP:
> # iw reg set JP
> # iw reg get | grep country
> country US:
>
> We're now stuck at the country code we were at before we put the invalid one
> in.
>
> In dmesg, this exchange looks like:
> # dmesg | grep cfg80211
> cfg80211: Calling CRDA to update world regulatory domain
> cfg80211: World regulatory domain updated:
> cfg80211: Calling CRDA for country: US
> cfg80211: Regulatory domain changed to country: US
> cfg80211: Calling CRDA for country: JP
> cfg80211: Regulatory domain changed to country: JP
> cfg80211: Calling CRDA for country: US
> cfg80211: Regulatory domain changed to country: US
> cfg80211: Calling CRDA for country: XX
> ... and we're stuck there.
>
> What looks to be happening is that the kernel uses udev to call /sbin/crda
> with a new COUNTRY= setting, but /sbin/crda bails out with -1 because of 'No
> country match in regulatory database', and never sends a netlink message
> back to the kernel to give it the regulatory information for that country.
> The kernel then seems to be stuck waiting for a message that will never
> come.
>
> The only way I can figure to unstick it is to reboot.

true you may be using old wireless-testing/compat wireless, i too got
this issue in Jan compat wireless

does this happens with the latest compat wireless. please check?
http://wireless.kernel.org/download/compat-wireless-2.6/


this would have fixed it

commit c989bb15e95a93e20fc86783264f6298116e8651
Author: Luis R. Rodriguez <lrodriguez@atheros.com>
Date:   Mon Apr 25 18:35:48 2011 -0700

    cfg80211: fix regresion on reg user timeout

    The patch "cfg80211: add a timer for invalid user reg hints"
    introduced a regression for the case where a secondary identical
    regulatory hint from a user is sent. What would happen is the
    second hint would schedule delayed work in to catch a timeout
    but since we are never processing it given that the hint was already
    applied we'd always hit the timeout and and restore regulatory
    settings back to world regulatory domain. This is fixed by simply
    avoiding sheduling work if the hint was already applied.

    Tested-by: Felix Fietkau <nbd@openwrt.org>
    Reported-by: Felix Fietkau <nbd@openwrt.org>
    Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
    Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 2714379..8982053 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1455,7 +1455,8 @@ static void reg_process_hint(struct
regulatory_request *reg_request)
         * We only time out user hints, given that they should be the only
         * source of bogus requests.
         */
-       if (reg_request->initiator == NL80211_REGDOM_SET_BY_USER)
+       if (r != -EALREADY &&
+           reg_request->initiator == NL80211_REGDOM_SET_BY_USER)
                schedule_delayed_work(&reg_timeout, msecs_to_jiffies(3142));
 }


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-- 
shafi