Fboesch at 09:13, 29 April 2006

2006-04-29T09:13:02Z

Fboesch: /* Setting Turbo modes in Linux */

2006-04-27T18:54:18Z

‎Setting Turbo modes in Linux

Rasto at 12:45, 27 January 2006

2006-01-27T12:45:17Z

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{| width="100%"
|style="vertical-align:top;padding-right:20px;width:10px;white-space:nowrap;" | __TOC__
|style="vertical-align:top" |
Atheros chipsets such as AR5001X+ found in [[IBM_11a/b/g_Wireless_LAN_Mini_PCI_Adapter]] and AR5004X found in [[IBM_11a/b/g_Wireless_LAN_Mini_PCI_Adapter_II]]
support atheros Super A and Super G (also known as Turbo) modes. These allow using of two channels for transmition between two Atheros devices,
allowing for speeds up to 108Mbit/s.
|}
These modes are however sometimes turned off on the WiFi card's EEPROM. When using [[Madwifi]] drivers, you can check, whether it is turned on.

With turbo modes on, madwifi driver should say something like this upon load.

{{cmdresult|wifi0: 11a rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps}}

{{cmdresult|wifi0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps}}

{{cmdresult|wifi0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps}}

{{cmdresult|wifi0: turboA rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps}}

{{cmdresult|wifi0: turboG rates: 6Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps}}

If it states onle turboG rate, it may be a problem with countrycode/region domain. Search [[Madwifi]] mailinglists for solution.
If the driver detects no turbo modes and setting region domain doesn't help, you may need to turn them on. This can probably be done
using Microsoft [[:Category:Windows|Windows]]. See [http://forum.thinkpads.com/viewtopic.php?t=4840 this] thread.

If you really want to get this to work, and you don't have Windows, it is still possible, so read on.

=== Setting Turbo modes in Linux ===
{{Todo| If anybody knows how to do this in a cleaner or nicer way, please rewrite this.}}
{{WARN| Big Fat Warning 1: Don't continue reading, unless you really have no other choice. Doing this is dangerous, may and probably will render your wireless device
nonfunctional and useless. You are doing it at your own responsibility! }}
{{WARN| Big Fat Warning 2: It is REQUIRED that you have some knowledge of C and and an idea how memory works. Withouth these, don't even bother.}}
{{WARN| Big Fat Warning 3: Proceed with doing this if and only if you at all points understand, what you are doing, and what do you need to do to reverse all changes
you have done.}}

First of all, you need to get drivers from the [http://www.ath-driver ath-driver] project to work. If these don't work (and they may not!),
trying this unnecessarily dangerous, as any slip will render your card useless, as [[Madwifi]] closed HAL won't load and you won't be able to access the EEPROM
to repair the damage.

Download [http://www.ksp.sk/~rasto/mod2.c], or find another ar5k modified to do something similar and modify it to do what you want.

The capability bits, located at 0x00c2 are described in eeprom.c of ath-driver. You need to set the "Disable turbo A" and "Disable turbo G" bits
to 0. Doing this straight away will however violate checksum for EEPROM, which is done XORing subsequent 2-bytes. They should XOR up to 0xffff.
Therefore, if you modify these two bits, you need to add 0x8008 (or whatever orig^new^0xffff gives) somewhere where the EEPROM is not used,
or find out the bits which are actually used
for this. For example bytes around 0x00cc seem to be empty (but may not be with your card! Check it!).
mod2.c contains two commented-out parts. The first can be used for the actual rewriting, the second to dump the relevant parts of EEPROM, which
are 0x00c0 to 0x00c0+832.
If anything bad happens, source code for the ath-driver can be of great help.

@@ Line 47: / Line 47: @@
 mod2.c contains two commented-out parts. The first can be used for the actual rewriting, the second to dump the relevant parts of EEPROM, which
 are 0x00c0 to 0x00c0+832.
-If anything bad happens, source code for the ath-driver can be of great help.
+If anything bad happens, source code for the ath-driver can be of great help.<br>

@@ Line 34: / Line 34: @@
 you have done.}}
-First of all, you need to get drivers from the [http://www.ath-driver ath-driver] project to work. If these don't work (and they may not!),
+First of all, you need to get drivers from the [http://www.ath-driver.org ath-driver] project to work. If these don't work (and they may not!),
 trying this unnecessarily dangerous, as any slip will render your card useless, as [[Madwifi]] closed HAL won't load and you won't be able to access the EEPROM
 to repair the damage.

Super A/G - Revision history

Fboesch at 09:13, 29 April 2006

Fboesch: /* Setting Turbo modes in Linux */

Rasto at 12:45, 27 January 2006