Return-path: Received: from mail-qw0-f46.google.com ([209.85.216.46]:63036 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750807Ab1DERmR (ORCPT ); Tue, 5 Apr 2011 13:42:17 -0400 Received: by qwk3 with SMTP id 3so379539qwk.19 for ; Tue, 05 Apr 2011 10:42:16 -0700 (PDT) Message-ID: <4D9B5473.6040003@lwfinger.net> Date: Tue, 05 Apr 2011 12:42:11 -0500 From: Larry Finger MIME-Version: 1.0 To: Gottfried Haider CC: linux-wireless@vger.kernel.org Subject: Re: rtl8192ce: odd ping behavior References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 04/03/2011 09:33 AM, Gottfried Haider wrote: > Dear linux-wireless, > > I am running 2.6.39-rc1 on a Lenovo Thinkpad x120e, which has a > Realtek b/g/n wireless adapter (PCI ID 10ec:8176). > >> From what I see through network-manager, the connection to my > (802.11g-type) access point/router is very stable, but I noticed that > browsing the web is a lot less smooth compared to my previous machine > with a b43 adapter (especially resolving hostnames and/or the initial > connection seems to take ages or entirely fails). > > I know that the rtl8192ce driver is pretty new, but I thought that I'd > point this out: > > When I am cloning a kernel git tree, the round-trip time I get for > pinging my router periodically goes up to 12 seconds, before briefly > jumping down to about 1.5 seconds and rising again: > > 64 bytes from 192.168.1.1: icmp_req=199 ttl=64 time=921 ms > 64 bytes from 192.168.1.1: icmp_req=200 ttl=64 time=651 ms > 64 bytes from 192.168.1.1: icmp_req=201 ttl=64 time=936 ms > 64 bytes from 192.168.1.1: icmp_req=202 ttl=64 time=862 ms > 64 bytes from 192.168.1.1: icmp_req=203 ttl=64 time=833 ms > 64 bytes from 192.168.1.1: icmp_req=204 ttl=64 time=945 ms > 64 bytes from 192.168.1.1: icmp_req=205 ttl=64 time=1003 ms > 64 bytes from 192.168.1.1: icmp_req=206 ttl=64 time=1058 ms > 64 bytes from 192.168.1.1: icmp_req=207 ttl=64 time=955 ms > 64 bytes from 192.168.1.1: icmp_req=208 ttl=64 time=1080 ms > 64 bytes from 192.168.1.1: icmp_req=209 ttl=64 time=1422 ms > 64 bytes from 192.168.1.1: icmp_req=210 ttl=64 time=1428 ms > 64 bytes from 192.168.1.1: icmp_req=211 ttl=64 time=1797 ms > 64 bytes from 192.168.1.1: icmp_req=212 ttl=64 time=2060 ms > 64 bytes from 192.168.1.1: icmp_req=213 ttl=64 time=2303 ms > 64 bytes from 192.168.1.1: icmp_req=214 ttl=64 time=2608 ms > 64 bytes from 192.168.1.1: icmp_req=215 ttl=64 time=2865 ms > 64 bytes from 192.168.1.1: icmp_req=216 ttl=64 time=3041 ms > 64 bytes from 192.168.1.1: icmp_req=217 ttl=64 time=3508 ms > 64 bytes from 192.168.1.1: icmp_req=218 ttl=64 time=3355 ms > 64 bytes from 192.168.1.1: icmp_req=219 ttl=64 time=3780 ms > 64 bytes from 192.168.1.1: icmp_req=220 ttl=64 time=3914 ms > 64 bytes from 192.168.1.1: icmp_req=221 ttl=64 time=4270 ms > 64 bytes from 192.168.1.1: icmp_req=222 ttl=64 time=4446 ms > 64 bytes from 192.168.1.1: icmp_req=223 ttl=64 time=4911 ms > 64 bytes from 192.168.1.1: icmp_req=224 ttl=64 time=5020 ms > 64 bytes from 192.168.1.1: icmp_req=225 ttl=64 time=5396 ms > 64 bytes from 192.168.1.1: icmp_req=226 ttl=64 time=5485 ms > 64 bytes from 192.168.1.1: icmp_req=227 ttl=64 time=5937 ms > 64 bytes from 192.168.1.1: icmp_req=228 ttl=64 time=6125 ms > 64 bytes from 192.168.1.1: icmp_req=229 ttl=64 time=6486 ms > 64 bytes from 192.168.1.1: icmp_req=230 ttl=64 time=6656 ms > 64 bytes from 192.168.1.1: icmp_req=231 ttl=64 time=6893 ms > 64 bytes from 192.168.1.1: icmp_req=232 ttl=64 time=7182 ms > 64 bytes from 192.168.1.1: icmp_req=233 ttl=64 time=7366 ms > 64 bytes from 192.168.1.1: icmp_req=234 ttl=64 time=7623 ms > 64 bytes from 192.168.1.1: icmp_req=235 ttl=64 time=7922 ms > 64 bytes from 192.168.1.1: icmp_req=236 ttl=64 time=8183 ms > 64 bytes from 192.168.1.1: icmp_req=237 ttl=64 time=8445 ms > 64 bytes from 192.168.1.1: icmp_req=238 ttl=64 time=8667 ms > 64 bytes from 192.168.1.1: icmp_req=239 ttl=64 time=8980 ms > 64 bytes from 192.168.1.1: icmp_req=240 ttl=64 time=8828 ms > 64 bytes from 192.168.1.1: icmp_req=241 ttl=64 time=9171 ms > 64 bytes from 192.168.1.1: icmp_req=242 ttl=64 time=9605 ms > 64 bytes from 192.168.1.1: icmp_req=243 ttl=64 time=9736 ms > 64 bytes from 192.168.1.1: icmp_req=244 ttl=64 time=10118 ms > 64 bytes from 192.168.1.1: icmp_req=245 ttl=64 time=10385 ms > 64 bytes from 192.168.1.1: icmp_req=246 ttl=64 time=10645 ms > 64 bytes from 192.168.1.1: icmp_req=248 ttl=64 time=10781 ms > 64 bytes from 192.168.1.1: icmp_req=249 ttl=64 time=11015 ms > 64 bytes from 192.168.1.1: icmp_req=250 ttl=64 time=11145 ms > 64 bytes from 192.168.1.1: icmp_req=252 ttl=64 time=11218 ms > 64 bytes from 192.168.1.1: icmp_req=253 ttl=64 time=11057 ms > 64 bytes from 192.168.1.1: icmp_req=254 ttl=64 time=11325 ms > 64 bytes from 192.168.1.1: icmp_req=255 ttl=64 time=11264 ms > 64 bytes from 192.168.1.1: icmp_req=256 ttl=64 time=11529 ms > 64 bytes from 192.168.1.1: icmp_req=257 ttl=64 time=10604 ms > 64 bytes from 192.168.1.1: icmp_req=258 ttl=64 time=9979 ms > 64 bytes from 192.168.1.1: icmp_req=259 ttl=64 time=9181 ms > 64 bytes from 192.168.1.1: icmp_req=260 ttl=64 time=8472 ms > 64 bytes from 192.168.1.1: icmp_req=261 ttl=64 time=7551 ms > 64 bytes from 192.168.1.1: icmp_req=262 ttl=64 time=6634 ms > 64 bytes from 192.168.1.1: icmp_req=263 ttl=64 time=5651 ms > 64 bytes from 192.168.1.1: icmp_req=264 ttl=64 time=4659 ms > 64 bytes from 192.168.1.1: icmp_req=265 ttl=64 time=3665 ms > 64 bytes from 192.168.1.1: icmp_req=267 ttl=64 time=1673 ms > 64 bytes from 192.168.1.1: icmp_req=268 ttl=64 time=918 ms > 64 bytes from 192.168.1.1: icmp_req=269 ttl=64 time=969 ms > > This is while cloning a git tree with about 135 KiB/s and no other > network activity. This does not appear to be showing up when I am > cloning with a higher throughput from git.kernel.org (say: 700 KiB/s) > - so I don't know whether the effect is caused by the slow speed > coming from occasional round-robin "outliers" or both the decreased > throughput and the increase in round-trip time are the result of > something else. > > > Maybe unreleated: When I enable a bit of debugging I see quite often > deauthentication/reauthentication messages - sometime as often as > every 25 seconds, and always with reason 7. > > Apart from that there is nothing in dmesg that stands out. If there is > anything I could help with in getting this device working, please let > me know. I repeated your test. My ping results were much better than yours: 1383 packets transmitted, 1367 received, 1% packet loss, time 1384611ms rtt min/avg/max/mdev = 1.317/3.732/384.371/10.962 ms I do not see the deauthentication/authentication results that you see. Those would definitely cause network delays. There are one difference in our systems. I have a 10ec:8178 device, but I have an 8176 here that I will try now. I have also received a new version of the driver from Realtek. If my 8176 has the same problems as yours, perhaps that will help. Larry