Return-path: Received: from bar.sig21.net ([80.81.252.164]:54930 "EHLO bar.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752838AbaH2OuN (ORCPT ); Fri, 29 Aug 2014 10:50:13 -0400 Date: Fri, 29 Aug 2014 16:50:02 +0200 From: Johannes Stezenbach To: Nate Carlson Cc: "linux-wireless@vger.kernel.org" , Larry Finger , Borislav Boev , ilw@linux.intel.com Subject: Re: Poor wifi performance on Intel 7260 Dual-Band AC Wifi card Message-ID: <20140829145002.GA28486@sig21.net> (sfid-20140829_165017_853121_544B5EA5) References: <53D7AEF5.5040907@lwfinger.net> <20140730110829.GA3563@sig21.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140730110829.GA3563@sig21.net> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, Jul 30, 2014 at 01:08:30PM +0200, Johannes Stezenbach wrote: > The question is how to go about testing. ISTR the Windows 8 driver > didn't have any issue and gave decent speed, but I don't have the > time to restore the Windows image for testing now. If Windows > and Linux use the same firmware I guess a comparison would > reveal if it's a driver of firmware issue. I had some spare time today to restore the Windows 8 image and test (praise Clonezilla!). The test is with an AP which (sometimes) sends broken beacons, so the result might not be viewed as valid by some, but I'm just comparing performance of different hardware and software under the same conditions. https://bugzilla.kernel.org/show_bug.cgi?id=78101 Earlier today I could connect with Linux and the Dual Band Wireless-AC 7260 gave me <50KB/s download speed (fetching kernel tarball from PC connected via 1G ethernet to the AP). An rt2800 usb dongle on the same machine gave me ~2.5MB/s. Currently Linux cannot connect at all (see bug 78101) due to the broken beacon. With Windows 8 (Driver Version 16.10.0.5, Driver Date 1/28/2014) I had no problems to connect, and got ~400KB/s download speed. (I confirmed via capture on the PC that the beacons were broken in the way described in bug 78101 during this test.) The rt2800 usb dongle gave me 2.4MB/s in Windows. I couldn't reboot the AP today to see if and how much the performance improves when the beacons are not broken. I'll do that when I have time. In the past, rebooting the AP did fix the connection issue (good beacon for some time), but did not turn the AC 7260 into a speed demon with the Linux driver. The AP only supports 2.4Ghz band 802.11n. > Otherwise I'm hoping Intel guys could provide some guidance for > testing so we could find the root cause. So far Intel did not show much interest in the issue, but a laptop user often has no control on the AP (travelling, hotels, conferences, etc.). IMHO Intel would their users a big favor if they spent some time optimizing for bad network conditions. The broken AP on my side will be replaced soon, but that's not the point of my complaint. Thanks, Johannes