Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933015Ab0HNIbu (ORCPT ); Sat, 14 Aug 2010 04:31:50 -0400 Received: from mx0.vr-web.de ([195.200.35.198]:38843 "EHLO mx0.vr-web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932739Ab0HNIbs (ORCPT ); Sat, 14 Aug 2010 04:31:48 -0400 From: Andreas X-Newsgroups: linux.kernel Subject: Re: rt61pci - bad performance Date: Sat, 14 Aug 2010 10:33:34 +0200 Organization: privat Message-ID: <4C6654DE.3070009@01019freenet.de> References:

Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@arcor.de Cc: Andrew Morton , Helmut Schaa User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; de; rv:1.9.3a6pre) Gecko/20100803 SeaMonkey/2.1a2 In-Reply-To: To: linux-kernel@vger.kernel.org X-BitDefender-Scanner: Clean, Agent: BitDefender Courier 3.0.2 on vrwf103, sigver: 7.28621 X-BitDefender-CF-Stamp: none Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5753 Lines: 134 Andrew Morton wrote: > (cc's added) > > On Sun, 08 Aug 2010 11:49:49 +0200 > Andreas wrote: > >> Hello! >> >> I've got the following hardware >> >> >> 01:05.0 Network controller: RaLink RT2561/RT61 rev B 802.11g >> Subsystem: Micro-Star International Co., Ltd. Device b833 >> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop- >> ParErr- Stepping- SERR- FastB2B- DisINTx- >> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=slow>TAbort- >> SERR-> Latency: 128, Cache Line Size: 64 bytes >> Interrupt: pin A routed to IRQ 21 >> Region 0: Memory at cc000000 (32-bit, non-prefetchable) [size=32K] >> Capabilities: [40] Power Management version 2 >> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA >> PME(D0-,D1-,D2-,D3hot-,D3cold-) >> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- >> Kernel driver in use: ndiswrapper >> >> >> running on a 32bit notebook with kernel 2.6.34-12-desktop (OpenSuSE >> 11.3). There is no difference between the compat-wireless-modules >> 2010-07-20 and the original modules shipped with the openSuSE 11.3 kernel. >> >> If the rt61-chip is connected to a AP using rt61pci, the best >> throughput, which can be achieved (at the same place), is about 1,7 >> MBytes/s. >> >> kernel: [ 656.112190] cfg80211: Calling CRDA to update world regulatory >> domain >> kernel: [ 656.112267] cfg80211: Calling CRDA for country: DE >> kernel: [ 656.169518] cfg80211: Regulatory domain changed to country: DE >> kernel: [ 656.169524] (start_freq - end_freq @ bandwidth), >> (max_antenna_gain, max_eirp) >> kernel: [ 656.169528] (2400000 KHz - 2483500 KHz @ 40000 KHz), >> (N/A, 2000 mBm) >> kernel: [ 656.169532] (5150000 KHz - 5350000 KHz @ 40000 KHz), >> (N/A, 2000 mBm) >> kernel: [ 656.169535] (5470000 KHz - 5725000 KHz @ 40000 KHz), >> (N/A, 2698 mBm) >> kernel: [ 656.206228] rt61pci 0000:01:05.0: PCI INT A -> GSI 21 (level, >> low) -> IRQ 21 >> kernel: [ 656.219941] phy0: Selected rate control algorithm 'minstrel' >> kernel: [ 656.222216] Registered led device: rt61pci-phy0::radio >> kernel: [ 656.222658] Registered led device: rt61pci-phy0::assoc >> kernel: notebook1 ifup: wlan0 device: RaLink RT2561/RT61 rev B >> 802.11g >> >> >> >> wlan0 IEEE 802.11bg ESSID:"--------" >> Mode:Managed Frequency:2.412 GHz Access Point: some AP >> Bit Rate=1 Mb/s Tx-Power=5 dBm >> Retry long limit:7 RTS thr:off Fragment thr:off >> Encryption key:off >> Power Management:off >> Link Quality=38/70 Signal level=-72 dBm >> Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 >> Tx excessive retries:0 Invalid misc:0 Missed beacon:0 >> >> The throughput is measured with ping -f -s 7000 and xosview -n. >> >> >> >> >> If I'm using ndiswrapper with the windows driver, first of all, I can >> see additional information in iwconfig: >> >> wlan0 IEEE 802.11g ESSID:"--------" >> Mode:Managed Frequency:2.412 GHz Access Point: some AP >> Bit Rate=54 Mb/s Tx-Power:20 dBm Sensitivity=-121 dBm >> RTS thr=2347 B Fragment thr=2346 B >> Encryption key:some key Security mode:restricted >> Power Management:off >> Link Quality:62/100 Signal level:-56 dBm Noise level:-96 dBm >> Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 >> Tx excessive retries:0 Invalid misc:0 Missed beacon:0 >> >> >> There is a switch for sensitivity (which is not supported with rt61pci) >> and the link quality compared with ndiswrapper is worse (38% to 62%). >> >> The following is remarkably too: >> ndiswrapper uses a Tx-Power of 20 dBm, rt61pci only 5 dBm. I don't know, >> why rt61pci uses 5 dBm. It's a hard limit and I can't set it on a value >> higher than 5 unless the driver is patched. Nevertheless, setting a >> higher value (of 20 dBm) by patch does not mean to get a better performance. That's wrong. I detected, that there is a great difference, because if you start the unpatched driver directly after the boot, the link isn't useable at all. I can't see any difference if the patched driver is loaded once and removed and the unpatched is loaded afterwards without rebooting between. The patch is: --- rt61pci.c.orig 2010-07-20 21:03:02.000000000 +0200 +++ rt61pci.c 2010-08-14 10:27:52.708008193 +0200 @@ -2661,13 +2661,17 @@ spec->channels_info = info; tx_power = rt2x00_eeprom_addr(rt2x00dev, EEPROM_TXPOWER_G_START); - for (i = 0; i < 14; i++) - info[i].tx_power1 = TXPOWER_FROM_DEV(tx_power[i]); + for (i = 0; i < 14; i++) { + // info[i].tx_power1 = TXPOWER_FROM_DEV(tx_power[i]); + info[i].tx_power1 = 25; + } if (spec->num_channels > 14) { tx_power = rt2x00_eeprom_addr(rt2x00dev, EEPROM_TXPOWER_A_START); - for (i = 14; i < spec->num_channels; i++) - info[i].tx_power1 = TXPOWER_FROM_DEV(tx_power[i]); + for (i = 14; i < spec->num_channels; i++) { + // info[i].tx_power1 = TXPOWER_FROM_DEV(tx_power[i]); + info[i].tx_power1 = 25; + } } return 0; Kind regards, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/