cfg80211: allow multiple driver regulatory_hints()

We add support for multiple drivers to provide a regulatory_hint()
on a system by adding a wiphy specific regulatory domain cache.
This allows drivers to keep around cache their own regulatory domain
structure queried from CRDA.

We handle conflicts by intersecting multiple regulatory domains,
each driver will stick to its own regulatory domain though unless
a country IE has been received and processed.

If the user already requested a regulatory domain and a driver
requests the same regulatory domain then simply copy to the
driver's regd the same regulatory domain and do not call
CRDA, do not collect $200.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/net/wireless.h b/include/net/wireless.h
index 21c5d966142d..9e73aae40c5d 100644
--- a/include/net/wireless.h
+++ b/include/net/wireless.h
@@ -187,6 +187,10 @@ struct ieee80211_supported_band {
  *      we will disregard the first regulatory hint (when the
  *      initiator is %REGDOM_SET_BY_CORE).
  * @reg_notifier: the driver's regulatory notification callback
+ * @regd: the driver's regulatory domain, if one was requested via
+ *      the regulatory_hint() API. This can be used by the driver
+ *      on the reg_notifier() if it chooses to ignore future
+ *      regulatory domain changes caused by other drivers.
  */
 struct wiphy {
         /* assign these fields before you register the wiphy */
@@ -213,6 +217,8 @@ struct wiphy {
 
         /* fields below are read-only, assigned by cfg80211 */
 
+        const struct ieee80211_regdomain *regd;
+
         /* the item in /sys/class/ieee80211/ points to this,
          * you need use set_wiphy_dev() (see below) */
         struct device dev;