Re: [PATCH 3.7 1/2] cfg80211: fix antenna gain handling

["Arend van Spriel" <arend@broadcom.com>]

On 10/06/2012 01:15 AM, Felix Fietkau wrote:
> On 2012-10-05 11:02 PM, Arend van Spriel wrote:
>> On 10/05/2012 10:22 PM, John W. Linville wrote:
>>> Anyone object?  I suspect that Johannes may be a little more
>>> busy/distracted than usual for the next few days/weeks...
>>>
>>> John
>>>
>>> On Wed, Oct 03, 2012 at 07:51:46PM +0200, Felix Fietkau wrote:
>>>> When not intersecting, orig->chan_mag is initialized to zero. Because of
>>>> that, the regulatory antenna gain limit never gets set.
>>>>
>>>> Signed-off-by: Felix Fietkau <nbd@openwrt.org>
>>>> Cc: stable@vger.kernel.org
>>>> ---
>>>>    net/wireless/reg.c |    3 +--
>>>>    1 file changed, 1 insertion(+), 2 deletions(-)
>>>>
>>>> diff --git a/net/wireless/reg.c b/net/wireless/reg.c
>>>> index 3b8cbbc..1a16f19 100644
>>>> --- a/net/wireless/reg.c
>>>> +++ b/net/wireless/reg.c
>>>> @@ -915,8 +915,7 @@ static void handle_channel(struct wiphy *wiphy,
>>>>
>>>>    	chan->beacon_found = false;
>>>>    	chan->flags = flags | bw_flags | map_regdom_flags(reg_rule->flags);
>>>> -	chan->max_antenna_gain = min(chan->orig_mag,
>>>> -		(int) MBI_TO_DBI(power_rule->max_antenna_gain));
>>
>> Just reading the commit message, I would think it better to initialize
>> chan->orig_mag to INT_MAX. Just my 0.02$
> I'm not sure it's useful for the driver to be able to add initial max
> antenna gain restrictions that way (which IMHO is the only point to
> using chan->orig_mag).
> I think it's better (and more predictable) to just stick to the power
> rules from the regulatory information.
>
> - Felix
>

Ok,

I was not understanding the usage scenario here. Your patch will ignore 
any driver initialized max antenna gain, which does not sound right to 
me. What if chan->orig_mag is a sensible (non-zero) value, which is 
lower than the value in regulatory power rule? Just seems that the patch 
changes more than the commit message it saying.

Gr. AvS