On 10/27/2014 03:18 PM, Adrien Decostre wrote:
> Hello Zefir,
> 
> Thanks a lot for your answer. This helps me a lot.
> If I correctly understand, the ability of ath9k to detect all pulses
> may also depend of the platform performances. So on an embedded
> platform with limited performances, we may observe more pulses losses
> than on a more powerful platform. Is this a right statement?
> 
No, there is no bottleneck in the platform performance. Presumed radar pulses 
are
reported as RX_ERROR descriptors and even lower end embedded systems are able to
handle the load. What makes the difference with the minimum pulse width is the
chip DFS engine's ability to isolate and identify very short spikes as potential
radar pulses.

This goes very deeply into material I had available under NDA while implementing
the DFS support for ath9k. If you intend to work on that topic, I encourage you 
to
contact the folks at QCA and join their 'NDA for Developers' program. The 
document
you want to read is 'Baseband DFS 2 (Radar) Micro-Architecture'.

> What about the CONFIG_ATH9K_DFS_CERTIFIED build options? Do we need it
> to enable the detection of 0.5usec. pulses?
> 
Yes, this driver specific flag (also available for 10k) you need to set to get 
the
DFS detector built (not related to pulse width). It essentially shifts the
responsibility of the product working in restricted bands to you / the 
manufacturer.


> Thanks in advance for your answer.
> 
> Best regards
> 
> Adrien
> 

Good Luck,
Zefir
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to