HostAP patches: I no longer maintain the patches, because they don't work for me with my current firmware version. Feel free to use them, but please, don't come and ask for any kind of support.

HostAP is a linux driver for prism2.5 chipset based WiFi cards. The project'shomepage can be found here

power, sensitivity, rate and retry restore patch

what has changed

What the first version (0.1) of this patch does. See the comments on subsequent versions (bottom of this page)

The card's txpower, sensitivity, rate and retry count can be set with
iwconfig. These settings only seem to work in master (AP) mode. Further,
the card often resets spontaneously, and these values are lost even in
the master mode. This patch tries to solve these (and many realated) problems.

problem: 
	txpower/rate/sens/retry settings lost spontaneously
solution: 
	fixed by automatically re-setting these values after card resets
	Note that the default values may be different than what you are
	used to. Set them up with iwconfig.



problem: 
	txpower/rate/sens/retry settings not working in managed mode
solution: 
	In managed mode, these values not only got lost after resets,
	but also after each asssociatin/disassociation with the AP.
	The patch seems to correct this at least for the txpower. I
	don't know how to check the remaining three values.

	The power stays where it should when the client is
	asociated with an AP. I don't know how to force this when it is
	not associated.


problem: 
	txpower stays on automatic setting (ALC=1), even after an
	"iwconfig ... txpower .. fixed"
solution:
	the driver would not set the ALC to 0 if it _thought_ it was set
	to 0 already. This is now fixed.
	"iwconfig .... txpower nnn" sets a fixed power of nnn
	"iwconfig .... txpower auto" sets ALC to 1

	Do not adjust the txpower by writing the card's registers
	directly (iwpriv ... writemif 62 ... ) - the driver does not
	know about this and will lose the settings eventually.
	

problem:
	iwconfig prints a different txpower than is actually stored in
	the register, read by "iwpriv ... readmif 62"
solution:
	fixed, now these values are the same


hack: 	
	The values of txpower entered and output to/by iwconfig claim to
	be in dBm. This is not true, they're just a very rough estimate.
	I disabled the conversion from/to dBm to/from the internal units.
	The parameters to iwconfig txpower, and the values printed as
	txpower by iwconfig, are now the same values you may have used
	already with readmif 62 / writemif 62

	These are somewhat unfriendly, but at least they don't give you
	a false feeling of reasonable settings

	The meaning of these values depend on the model of your card.
	We have a calibration for ZCOM XI-626 and Alphawave here:
	http://www.czfree.net/forum/showthread.php?s=&threadid=2882 
	
	Indipendent of the actual card model, a value of 128 is always
	the maximum power ... increasing the value towards 255 will decrease 
	the txpower ... then if you overflow to 0, the txpower decreases
	further as you approach 127. 127 is the minimum txpower. This is
	the default value set by this patch:

	!!! the default txpower is set to minimum power (127). Don't
	expect the connection to work well with this setting. Determine
	an appropriate value and set it using iwconfig .... txpower x !!!


	If you want the old and confusing conversion, uncomment the line
	#define PRISM2_DBM_CONVERSION in driver/modules/hostap_config.h

known problems

The patch is reported not to work with firmware version 1.3.6. The reported problem was, that in client mode, the patched station did not associate to the AP.

All testing and debugging I have done so far was on 1.5.6, so this is what I recommend. I don't have time nor hardware to test with different versions.

People also reported that with 1.7.4 a and 1.8.0 the txpower restore did not work. Again ... use 1.5.6 :) Update: on Jan 22 2004 I flashed my cards to 1.7.4, and the patch really doesn't work. I will try to fix it in the future.

getting and applying the patch

Download the desired version of the patch

Unpack the hostap package. Change to the directory extracted from the archive and do: patch -p1 <path_to_the_downloaded_patch_file

version 0.2:
- on my system, setting rate, sens or retry after resets severely decreased stability. Your mileage may vary. Restoring txpower is the original purpose of the patch and it seems to work well. What should and should not be restored can be specified at the end of hostap_config.h. The default is to restore the txpower only.
- restoring txpower after association in managed mode did not work in 0.1. It should be fixed now, rate and sens will never be restored after association anymore, as this caused the trouble.
- fixed a minor bug in prism2_ioctl_siwtxpow
- in hostap-0.0.4, txpower control is disabled by default. The patch enables it by #defining RAW_TXPOWER_SETTING in hostap_config.h

hostap-0.0.1-psrrr-0.2.patch (tested)
hostap-0.0.2-psrrr-0.2.patch (tested)
hostap-0.0.3-psrrr-0.2.patch (tested)
hostap-0.0.4-psrrr-0.2.patch (tested)
hostap-2003-09-24-psrr-0.2.patch (for a cvs snapshot - tested)
hostap-driver-0.1.0-psrrr-0.2.patch (tested)
hostap-driver-0.2.0-psrrr-0.2.patch (tested)
hostap-driver-0.3.7-psrrr-0.2.patch (Thanks to Jakub Horky)
hostap-2.6.14.3-psrrr-0.2.patch (against the whole kernel tree)
hostap-2.6.17.6-psrrr-0.2.patch (against the whole kernel tree)

version 0.1:
This is the first released version.

hostap-2002-10-12-psrrr-0.1.patch
hostap-0.0.1-psrrr-0.1.patch

If you alter it for other versions of hostap, you can mail it to me and I'll post it here.

Any feedback will be greatly appreciated. here are my contact details

Fri Dec 17 20:32:35 CET 2004