Handling user regdom hints while having intersected world regdom

Commit Message

Peter Große Sept. 29, 2018, 12:13 a.m. UTC

Hi.

When a setup has multiple wifi cards anounncing different regdoms, the
regularitory subsystem stores an intersected world regdom using aplha2 "98".

I wonder what the correct result should be, when I call "iw reg set 00" or with
any other country code?

Because in my system with multiple cards nothing happened.

I added a lot of debug messages and I found the request is rejected with
REG_REQ_IGNORE in __reg_process_hint_user (in net/wireless/reg.c:2371).

In this check, last_request is considered (the request before my user request),
which in my case was the driver request for the second card leading to the
intersected regdom. But since "98" doesn't match the regdom provided by the
driver, the check returns true and the request gets rejected.

The comment above the check mentions not yet processed requests, but I doubt
that checking the current regdom against the last_request regdom helps in my
case. But from reading the code I got there is a "processed" flag for each
requst.

So maybe a patch like below is enough? Or are there more things to consider?
Or maybe I'm wrong and the current behavior is intended?!

Regards
Peter

Comments

Tom Psyborg Oct. 19, 2018, 4:26 p.m. UTC | #1

Hi

After this change, on interface reconfig regdomains for both int. and
usb radio are no longer 98. instead they are both set to US (int.
radio regdomain) while usb should be set to GB. I am not sure if there
is an easy way to handle this.
Bad thing is that regdomains still intersect for few seconds on usb
card insert and during that time int. radio resets it's txpower to
max->described in this bug issue:
https://bugs.openwrt.org/index.php?do=details&task_id=1745

Patch

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 4fc66a117b7d..ed4543c7b255 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -2428,15 +2428,15 @@  __reg_process_hint_user(struct regulatory_request
*user_request) /*
         * Process user requests only after previous user/driver/core
         * requests have been processed
         */
        if ((lr->initiator == NL80211_REGDOM_SET_BY_CORE ||
             lr->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
             lr->initiator == NL80211_REGDOM_SET_BY_USER) &&
-           regdom_changes(lr->alpha2))
+           !lr->processed)
                return REG_REQ_IGNORE;
 
        if (!regdom_changes(user_request->alpha2))
                return REG_REQ_ALREADY_SET;
 
        return REG_REQ_OK;
 }