From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from relay3-d.mail.gandi.net ([217.70.183.195]:60582 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753129Ab1HQCvu (ORCPT ); Tue, 16 Aug 2011 22:51:50 -0400 Date: Tue, 16 Aug 2011 19:51:43 -0700 From: Josh Triplett To: linux-wireless@vger.kernel.org Cc: Jamey Sharp Subject: EINVAL when setting 802.11a channel in Ad-Hoc mode Message-ID: <20110817025141.GA4529@leaf> (sfid-20110817_045153_283507_FC25B957) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: We're trying to run 802.11a in Ad-Hoc mode. However, when we get to the point of setting the channel, we almost always get EINVAL back from the kernel. We ran the following series of commands: wlan=wlan3 iwconfig $wlan mode Ad-Hoc ifconfig $wlan up iwconfig $wlan essid PSAS-flight-computer iwconfig $wlan channel 36 The channel command almost always got back an EINVAL. This occurred on three different wifi chipsets: a USB ar9170 (with either carl9170 or the older ar9170usb driver), a USB rt2800usb, and iwlwifi with a Lenovo X220. In the former two cases, it occurs on both x86 (the aforementioned X220) and powerpc (an MPC5200). More strangely, the channel command would *sometimes* successfully set the channel without error. Have we done something wrong with the sequence of commands above? Why might we get EINVAL when setting a valid channel? What next steps should we take to debug this? Currently about to compile in function_graph tracing and start walking through the execution of SIOCSIWFREQ looking for what generates the EINVAL. - Josh Triplett