Re: [PATCH] wifi: cfg80211: allow reg update by driver even if wiphy->regd is set

[Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>]

On 4/20/2023 11:13 PM, Raj Kumar Bhagat wrote:
> Currently regulatory update by driver is not allowed when the
> wiphy->regd is already set and drivers_request->intersect is false.
>
> During wiphy registration, some drivers (ath10k does this currently)
> first register the world regulatory to cfg80211 using
> wiphy_apply_custom_regulatory(). The driver then obtain the current
> operating country and tries to update the correct regulatory to
> cfg80211 using regulatory_hint().
>
> But at this point, wiphy->regd is already set to world regulatory.
> Also, since this is the first request from driver after the world
> regulatory is set this will result in drivers_request->intersect
> set to false. In this condition the driver request regulatory is not
> allowed to update to cfg80211 in reg_set_rd_driver(). This restricts
> the device operation to the world regulatory.
>
> This driver request to update the requlatory with current operating

nit: s/requlatory/regulatory/

> country is valid and should be updated to cfg80211. Hence allow
> regulatory update by driver even if the wiphy->regd is already set
> and driver_request->intersect is false.
>
> Signed-off-by: Raj Kumar Bhagat <quic_rajkbhag@xxxxxxxxxxx>

Reviewed-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>

> ---
>   net/wireless/reg.c | 9 ++++-----
>   1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/net/wireless/reg.c b/net/wireless/reg.c
> index 0d40d6af7e10..6cf0bc386f94 100644
> --- a/net/wireless/reg.c
> +++ b/net/wireless/reg.c
> @@ -3833,7 +3833,7 @@ static int reg_set_rd_driver(const struct ieee80211_regdomain *rd,
>   {
>   	const struct ieee80211_regdomain *regd;
>   	const struct ieee80211_regdomain *intersected_rd = NULL;
> -	const struct ieee80211_regdomain *tmp;
> +	const struct ieee80211_regdomain *tmp = NULL;
>   	struct wiphy *request_wiphy;
>   
>   	if (is_world_regdom(rd->alpha2))
> @@ -3856,10 +3856,8 @@ static int reg_set_rd_driver(const struct ieee80211_regdomain *rd,
>   	if (!driver_request->intersect) {
>   		ASSERT_RTNL();
>   		wiphy_lock(request_wiphy);
> -		if (request_wiphy->regd) {
> -			wiphy_unlock(request_wiphy);
> -			return -EALREADY;
> -		}
> +		if (request_wiphy->regd)
> +			tmp = get_wiphy_regdom(request_wiphy);
>   
>   		regd = reg_copy_regd(rd);
>   		if (IS_ERR(regd)) {
> @@ -3868,6 +3866,7 @@ static int reg_set_rd_driver(const struct ieee80211_regdomain *rd,
>   		}
>   
>   		rcu_assign_pointer(request_wiphy->regd, regd);
> +		rcu_free_regdom(tmp);
>   		wiphy_unlock(request_wiphy);
>   		reset_regdomains(false, rd);
>   		return 0;