How to access the CCA related operation

Ben Greear greearb at
Mon Aug 24 09:32:32 PDT 2015

It is in firmware, and you cannot reliably poke it through the driver
read/write register API because each time the radio resets (channel change, etc), it is
liable to re-write the CCA registers back to default values.

There is a large list of registers with 'CCA' in the name, but I don't
know what they really mean, and I had hard time getting that info out
of QCA.  If you have any better luck, please post whatever you can


On 08/23/2015 11:21 PM, Seowoo Jang wrote:
> Hello,
> We are trying to evaluate our idea on 802.11ac protocol with Atheros qca9880
> / ath10k driver.
> We would like to be able to access/know the result of the CCA (clear channel
> assessment) operation
> or the level of interference on the carrier when we need.
> We have dug into the driver files and concluded that the CCA related values
> are likely
> in the firmware or on the registers of the hardware.
> And please correct us if we are thinking wrong.
> We would appreciate the help if someone can give us some starting points,
> such as the address of the register that stores the carrier sensing values
> (CCA values)
> or the result of it (whether the carrier is busy or idle), to investigate.
> The chipset we are using is compex WLE900VX-7AA.
> We are currently using Ubuntu 14.04.03 with kernel version 4.1.5,
> but we can use any versions of OS and kernel if they support 802.11ac
> bandwidth.
> Thank you for help in advance.
> -------------------------------
> Seowoo Jang, Ph.D.
> Ubiquitous Network Laboratory
> EECS, Seoul National University
> CEL   +82-10-3723-3401
> E-mail swjang at
> -------------------------------
> _______________________________________________
> ath10k mailing list
> ath10k at

Ben Greear <greearb at>
Candela Technologies Inc

More information about the ath10k mailing list