Re: [RFC 4/6] ath9k: add DFS build parameter

[Felix Fietkau <nbd@openwrt.org>]

On 2011-10-04 11:55 AM, Zefir Kurtisi wrote:
> On 10/03/2011 08:26 PM, Luis R. Rodriguez wrote:
>>  On Mon, Oct 3, 2011 at 3:29 AM, Zefir Kurtisi<zefir.kurtisi@neratec.com>  wrote:
>>>
>>>  Signed-off-by: Zefir Kurtisi<zefir.kurtisi@neratec.com>
>>>  ---
>>>   drivers/net/wireless/ath/ath9k/Kconfig  |    7 +++++++
>>>   drivers/net/wireless/ath/ath9k/Makefile |    2 ++
>>>   2 files changed, 9 insertions(+), 0 deletions(-)
>>>
>>>  diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig
>>>  index d9c08c6..adddcca 100644
>>>  --- a/drivers/net/wireless/ath/ath9k/Kconfig
>>>  +++ b/drivers/net/wireless/ath/ath9k/Kconfig
>>>  @@ -58,6 +58,13 @@ config ATH9K_RATE_CONTROL
>>>           Say Y, if you want to use the ath9k specific rate control
>>>           module instead of minstrel_ht.
>>>
>>>  +config ATH9K_DFS
>>>  +       bool "Atheros ath9k DFS support"
>>>  +       depends on ATH9K
>>>  +       default y
>>
>>  At this point selecting y does nothing. Leave this patch out until
>>  selecting "y" means something.
>>
> What do you mean by 'nothing'? It allows you to select DFS as ath9k feature in your kernel configuration, or? Though, I agree that enabling it by default is not a good idea.
>
>>  Default should be n, and in particular Atheros itself can only likely
>>  commit to supporting DFS for AR9003 when it finds resources to do so
>>  as well as properly test it, so DFS support kconfig should state this.
>>  If someone wants to step up to completely support all bugs for older
>>  families that is their prerogative but we cannot commit to it, due to
>>  the regulatory considerations though unless this happens this cannot
>>  and should not be enabled for older families in code.
>>
> In fact, AR9003 is the platform we are interested in. Although it
> seems that older chipsets do also detect pulses with this patches
> (AR9280 does, IIRC), I agree to limit DFS support to AR9003 (and later).
> This should be easily possible by setting priv_ops->set_radar_params for
> AR9003 only. I'll remove it for AR5008 in my v2 RFC.
Please don't remove support code for older hardware. I'm fine with 
adding a SREV check that prevents it from being enabled by default on 
older hardware, but eventually I will need at least AR9280 DFS support 
for a few devices in OpenWrt.

- Felix