From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtpout3.wanadoo.co.uk ([80.12.242.59]:33329 "EHLO smtpout.wanadoo.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755674Ab3EHNvp (ORCPT ); Wed, 8 May 2013 09:51:45 -0400 Date: Wed, 8 May 2013 15:51:44 +0200 (CEST) From: nick@nhthomas.freeserve.co.uk Reply-To: nick@nhthomas.freeserve.co.uk To: linux-wireless@vger.kernel.org Message-ID: <7566504.38231368021104217.JavaMail.www@wwinf3714> (sfid-20130508_155149_068268_7C166D58) Subject: Wifi signal level differences MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, I have an Atheros ath6kl_usb based wifi dongle. I am using it with an embedded project. The driver code can be built for either X86 or sh4 hardware - so I can also use the same USB wifi dongle on my Fedora 12 Linux PC or plugged in to the embedded device. It's working fine in both situations. But, I notice that the signal level reported in /proc/net/wireless is slightly different between the two units. Note, I am using the same physical Atheros wifi dongle, and moving it from one device to the other to this test. I notice that when using the X86 PC I see a signal level of -61, which is marginally better than the -66 I see in the embedded device. I know that this isn't an exact science - but using a short USB extension lead I can orientate the wifi dongle to be in the same place and orientation when plugged in to either device. So, I would expect the wifi signal strength to be reported the same !? I know there are many differences between my Fedora 12 PC, and the embedded STLinux project - not least that the driver is compiled using different compilers. But, I was wondering what else could explain the difference in signal levels between the two? Also, which part of the driver code is responsible for reading/calculating the signal level value? Regards Nick