netdev - Re: [PATCH] cfg80211/nl80211: add wifi tx power mode switching support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1462951291.2869.4.camel@sipsolutions.net>
Date:	Wed, 11 May 2016 09:21:31 +0200
From:	Johannes Berg <johannes@...solutions.net>
To:	Wei-Ning Huang <wnhuang@...omium.org>,
	Linux-Wireless <linux-wireless@...r.kernel.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Sameer Nanda <snanda@...omium.org>,
	Todd Broch <tbroch@...omium.org>, davem@...emloft.net,
	netdev@...r.kernel.org
Subject: Re: [PATCH] cfg80211/nl80211: add wifi tx power mode switching
 support

On Thu, 2016-05-05 at 14:44 +0800, Wei-Ning Huang wrote:
> Recent new hardware has the ability to switch between tablet mode and
> clamshell mode. To optimize WiFi performance, we want to be able to
> use different power table between modes. This patch adds a new
> netlink message type and cfg80211_ops function to allow userspace to
> trigger a power mode switch for a given wireless interface.

I'm not a fan of this at all. Too much magic.

FWIW, we implemented something similar, currently with vendor commands,
that simply allows to set the TX power in a more controlled fashion,
i.e. allows setting TX power per band/channel range. For our device
it's only 2.4 GHz vs. 5.2 GHz, but I can imagine that you might want to
split it a bit further, so perhaps we need to advertise those ranges
somehow.

johannes