Cannot use 80MHz channel

Michal Kazior michal.kazior at
Wed Dec 18 01:15:00 EST 2013

On 17 December 2013 22:51, Li Sun <lsun3 at> wrote:
> Hi,
> I am trying to play around with the ath10k driver. I have two Qualcomm
> Atheros QCA9880 Version 2 802.11ac chipsets. I put one of the cards in
> AP mode using hostapd and connect the other one as a client.
> I am using the hostapd config mentioned at
> "". The
> client connects but the throughput is just around 300 Mbps (suggesting
> 40 MHz channel-width) and NOT any higher. It seems I am unable to use
> the 80 MHz channel-width. Also, when I checked the kernel logs
> (dmesg), I found the following message on the client side only:
> capabilities/regulatory prevented using AP HT/VHT configuration, downgraded
> Could this problem be related to CRDA ? I am in the US.

Check output of `iw reg get`. If you see no entries with `@ 80` you
have to upgrade your regdb.


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