Re: [PATCH 1/2] cfg80211: Support for automatic channel selection in AP mode

[Johannes Berg <johannes@sipsolutions.net>]

On Mon, 2012-06-18 at 16:30 +0530, Vivek Natarajan wrote:
> If the driver sets WIPHY_FLAG_SUPPORTS_ACS, auto_channel_select
> is passed to the driver as ap settings and frequency setting is
> skipped. When the AP mode comes up in the new channel, it is 
> intimated to cfg80211 through cfg80211_ch_switch_notify which
> in turn notifies the channel information to wpa_supplicant
> through CH_SWITCH event.
> 
> Signed-off-by: Vivek Natarajan <nataraja@qca.qualcomm.com>
> ---
> v2: Add a new flag attribute for _START_AP command to indicate ACS request.
>     Update the channel/frequency information using ch_switch_notify
>     once the driver (firmware) has selected the channel.
> 
> For P2P, the operating channel needs to be known before group negotiation starts.
> This is true in case of P2P GO or client. It needs a separate p2p command from
> wpa_cli to get the acs-based best channel information from the driver.

So .. is there any reason to not do only the second, and then pass that
channel back here instead?

johannes