From mboxrd@z Thu Jan 1 00:00:00 1970 From: Larry Finger Subject: Re: [PATCH] bcm43xx-softmac: Further improvement in wireless statistics Date: Thu, 13 Jul 2006 23:32:26 -0500 Message-ID: <44B71E5A.3000905@lwfinger.net> References: <44B3CC25.7060305@lwfinger.net> <1152646370.27683.2.camel@localhost.localdomain> <44B474AF.6010907@lwfinger.net> <1152848265.2584.48.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: John Linville , netdev@vger.kernel.org, Jean Tourrilhes Return-path: Received: from mtiwmhc13.worldnet.att.net ([204.127.131.117]:45727 "EHLO mtiwmhc13.worldnet.att.net") by vger.kernel.org with ESMTP id S1161257AbWGNEcb (ORCPT ); Fri, 14 Jul 2006 00:32:31 -0400 To: Dan Williams In-Reply-To: <1152848265.2584.48.camel@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Dan Williams wrote: > > Jean, what's the official word on range->max_qual.level? > > I don't know where I came up with the requirement that max_qual.level > must be 0 to indicate that the units are in dBm (as opposed to RSSI), > but it might well have been because we had no way to detect RSSI vs. dBm > before IW_QUAL_DBM was added as a flag in WE-19, and therefore using > level = 0 was the only reliable way because 0 is the theoretical "max" > level that most cards can handle. > > So if you want to express your quality in dBm, you have a choice; either > set IW_QUAL_DBM explicitly and do what you want with max_qual.level, or > set your max_qual.level to 0. That's my interpretation, of course I > could be wrong. > > Furthermore, there's no point to setting your max_qual.level to be the > lowest level, since that's what your max_qual.noise is!!! > max_qual.noise is the noise floor of your card and that effectively _is_ > the lowest level at which your card can operate. > > In the ideal world, which we are now much closer to, we could _require_ > that IW_QUAL_DBM was set, otherwise values would be interpreted as RSSI. > And we can if the driver's we_source_version is >= 19. I agree, it's > all quite confusing for starters. Setting IW_QUAL_DBM when updating does make /proc/net/wireless report level and noise as negative numbers. Thanks for pointing me in that direction. I also tried both 0 and -100 as the qual_max values. The range is definitely better with -100 than with 0. Larry