From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from odin.sdf-eu.org ([178.63.35.194]:55278 "EHLO sdfeu.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750884AbbJaURh (ORCPT ); Sat, 31 Oct 2015 16:17:37 -0400 Received: from vaygach (199-119-235-162.eng.wind.ca [199.119.235.162] (may be forged)) (authenticated (0 bits)) by sdfeu.org (8.14.8/8.14.3) with ESMTP id t9VK6snM016548 (using TLSv1/SSLv3 with cipher AES128-GCM-SHA256 (128 bits) verified NO) for ; Sat, 31 Oct 2015 20:06:58 GMT Date: Sat, 31 Oct 2015 14:10:57 -0600 From: Gerrit Renker To: linux-wireless@vger.kernel.org Subject: [WEXT/nl80211] few API questions Message-ID: <20151031141057.324b3274@vaygach> (sfid-20151031_211741_208909_2F737FC0) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-wireless-owner@vger.kernel.org List-ID: I have a few short nl80211 API questions to help convert a userland program from WEXT to nl80211 [1]. The iw code has been helpful, and I have used bits of it so far. When it comes to kernel components, though, I don't understand that code well enough; so I'd appreciate help with the following: 1. Signal Level Units This refers to station signal level in status ASSOCIATED, AUTHENTICATED, or IBSS_JOINED. Q: Are the values reported via NL80211_STA_INFO_SIGNAL{,_AVG} in xxx always in dBm, or if not, what information should be used (NL80211_BSS_SIGNAL_MBM, NL80211_BSS_SIGNAL_UNSPEC). The wext API sets the unit via iw_quality.updated flags (IW_QUAL_DBM), is the same needed in nl80211? 2. Noise Level It seems that the WEXT API does no longer support reporting noise floor levels (IW_QUAL_NOISE_INVALID is always set). Q: Is it correct to use NL80211_SURVEY_INFO_NOISE for the active channel (NL80211_SURVEY_INFO_IN_USE) as replacement (header says it is dBm)? 3. Link Quality WEXT has the concept of a link quality metric (iw_quality.qual). Q: Given access to signal levels in dBm or mBm, looking at cfg80211_wireless_stats(); would be correct to replace the call to SIOCGIWSTATS by using the nl80211 values in (1) and simply interpret -110dBm and -40dBm as ends of a quality scale from 0..70? Thanks in advance, Gerrit [1] https://github.com/uoaerg/wavemon/tree/development