
Intel(R) PRO/Wireless 3945ABG Network Connection driver for Linux* in 
support of:

Intel(R) PRO/Wireless 3945ABG Network Connection Adapter
Intel(R) PRO/Wireless 3945BG Network Connection Adapter

Copyright (C) 2005 - 2006, Intel Corporation

ISSUES

Version: 1.0.3
Date   : May 02, 2006
------------------------------

The following are the most common issues reported by users at the time of
this release.  

Additional details may be found at http://bughost.org by entering in the bug
number referenced.

Problems summarized below:

1. Strongest AP is not always selected for association
2. IEEE 802.11b transmit is faster than receive at lower signal levels
3. Cannot associate with open networks using LEAP authentication
4. Cannot associate with access points set to only support a single OFDM rate
5. Kernel panic while transferring large amounts of data
6. Available free memory depletes while transferring large amounts of data
7. Restricting wireless bands from BG to A while in ad-hoc mode causes problems
8. Restricting ad-hoc mode to a single rate results in a microcode SYSASSERT
9. Configuring PSP mode while in an ad-hoc network results in packet loss
10. Disassociation and association timeouts while using hidden networks
11. Scanned access points count is smaller while associated
12. Error messages in kernel log during large data transmissions
13. iwspy threshold events are not triggered
14. Problems obtaining a DHCP lease with some dhcp client/server combinations
15. Cannot use WPA with EAP with older wpa_supplicant versions
16. Problems with WPA with AES and fragmentation 
17. Problem obtaining an IRQ (driver does not responsd) if ACPI disabled.

Issue summaries:

1. Strongest AP is not always selected for association

There is a bug in the ieee80211 subsystem available in the Linux kernel that
can cause the AP selection logic to not pick the strongest access point.  If
you know a specific network has a better signal than the one you are 
associated with, you can force the driver to use that access point by using
the iwconfig's 'ap' command (see the iwconfig man page)

Upgrading to ieee80211-1.1.13 or newer should correct the above problem.

http://bughost.org/bugzilla/show_bug.cgi?id=958


2. IEEE 802.11b transmit is faster than receive at lower signal levels

If you are using an 802.11b wireless network, you may notice that as the 
signal level of the network associated with decreases, the driver's
ability to receive TCP data decreases faster than the ability to transmit
TCP data. In high signal levels and closer proximity to the access point,
data rates are as expected.  

http://bughost.org/bugzilla/show_bug.cgi?id=959


3. Cannot associate with open networks using LEAP authentication

If your wireless network is configured to use no encryption, but does use
LEAP authentication, you may not be able to associate with it.  To work 
around this problem, configure a static WEP key on your access point and
configure the same WEP key on the client.

http://bughost.org/bugzilla/show_bug.cgi?id=960


4. Cannot associate with access points set to only support a single OFDM rate

If your access point is configured to only support a single OFDM receive
data rate, you may not be able to associate with it. To work around this issue,
configure your AP to use more than one OFDM (802.11G) data rate.

http://bughost.org/bugzilla/show_bug.cgi?id=961


5. Kernel panic while transferring large amounts of data

We have had one report of a kernel panic during file transfers.  While we
have not been able to reproduce the failure, we are documenting it here.
We are currently investigating the issue.  If you experience any kernel
panics or crashes, please see the bug referenced below; and provide any
information related to your specific issues; information that you may have
could help in resolving the issue.

There is currently no known workaround.  The problem has reportedly only 
impacted one user to date.

http://bughost.org/bugzilla/show_bug.cgi?id=931


6. Available free memory depletes while transferring large amounts of data

After transferring a significant amount of data (on the order of gigabytes)
you may notice a depletion of system memory resources.  We are currently
investigating this issue to determine if there is a memory leak in the
driver or an issue with how the driver is working with the rest of the 
kernel.

Currently unloading the module does not restore the systems total free
memory.  Investigation continues to determine if the memory will eventually
be reclaimed and made available by the kernel in low memory situations, or
moved to swap space.  


http://bughost.org/bugzilla/show_bug.cgi?id=962


7. Restricting wireless bands from BG to A while in ad-hoc mode causes problems

If you configure the wireless card into ad-hoc mode in a BG network to
limit the supported bands to only support A, the driver may fail with
a microcode error message displayed in the kernel log.

Workaround: Set the mode to ABG and then manually change the
channel to the channel you want for the ad-hoc network (ensuring that it is
a valid channel for ad-hoc) and then set the mode to A only.  

See the README.ipw3945 for information on setting the mode.

http://bughost.org/bugzilla/show_bug.cgi?id=934


8. Restricting ad-hoc mode to a single rate results in a microcode SYSASSERT

If you configure the system to only support a single data rate while in
an ad-hoc network, you may experience a microcode error and driver restart.
Setting data rates is achieved via iwconfig's rate command.

The workaround is to not set an explicit single data rate while in ad-hoc
mode.  

http://bughost.org/bugzilla/show_bug.cgi?id=963


9. Configuring PSP mode while in an ad-hoc network results in packet loss

If you configure the system to use PSP (via iwpriv set_power) while in
an ad-hoc network, you will experience significant packet loss in the
network.

The workaround is to not use PSP mode in an ad-hoc network.

http://bughost.org/bugzilla/show_bug.cgi?id=968


10. Disassociation and association timeouts while using hidden networks

If you disable broadcasting of the SSID on your wireless network, you may
experience intermittent network disassociation and periodic inability to
associate with your network.

If you experience this problem, the current workaround is to enable SSID 
beaconing from the AP.

http://bughost.org/bugzilla/show_bug.cgi?id=964


11. Scanned access points count is smaller while associated

While associated, scanning may not find as many access points as reliably
as scanning while not associated.  This is a result of the amount of time
that can be spent out of the associated channel without disrupting the
current association.  Scan information defaults to expiring if a network
does not receive a beacon or probe response within 15 seconds.

Workaround: Try scanning, then wait a second or two, and then scan again.
The second and subsequent scans should collect more of the scan data that
may have been missed in the first scan.  You can also increase the default
maximum scan age by specifying the maximum age of a network in milliseconds
to the sysfs entry 'scan_age'.  See README.ipw3945 for more information.

http://bughost.org/bugzilla/show_bug.cgi?id=965


12. Error messages in kernel log during large data transmissions

You may occassionally see the error message: 

ipw3945: No space for Tx
ipw3945: Error sending ADD_STA: ipw_queue_tx_hcmd failed: -28

These messages can be ignored.

http://bughost.org/bugzilla/show_bug.cgi?id=941


13. iwspy threshold events are not triggered

If you configure a threshold event based on signal level, that event may
not be triggered when the threshold is crossed.

No known workaround.

http://bughost.org/bugzilla/show_bug.cgi?id=966


14. Problems obtaining a DHCP lease with some dhcp client/server combinations

Some dhcp clients have problems in communicating with specific dhcp
servers while obtaining frequent and renewed leases.  If your dhcp client
stalls while trying to obtain an IP address and you are associated to a 
valid network (with the correct WEP key if appropriate), you can try the
following workaround:

  1.  Kill any current instances of your dhcp client:
	% killall dhclient || killall dhdpcd
	% rm /var/run/{dhcpcd,dhclient}*pid
  2.  Remove any cached lease files
	See the man page for your dhcp client to determine which files
	these are.  It is usually one of the following:
	% rm /var/run/cache/dhcpcd-* 
	% rm /var/lib/dhcp/dhclient*leases
  3.  Restart the dhcp client
	% dhclient eth1 || dhcpcd eth1


15. Cannot use WPA with EAP with older wpa_supplicant versions

Users have reported problems using older (0.3.x) versions of 
wpa_supplicant with various authentication modes (WPA PSK, etc.).  
If you experience problems using wpa_supplicant, please upgrade to the 
latest version of the supplicant (0.4.6 or newer)


16. Problems with WPA with AES and fragmentation 

In some configurations, setting fragmentation on client results in 
AES not functioning.  If you experience this behavior, please try
with fragmentation disabled or check with your AP manufacturer for 
a firmware upgrade.


17. Problem obtaining an IRQ (driver does not responsd) if ACPI disabled.

Some laptops may have a problem with their BIOS in conjunction with 
Linux such that if ACPI is disabled (via acpi=off on the kernel command 
line or by not compiling it into the kernel), the driver will not be 
able to correctly obtain an IRQ needed to operate the device.

The current work around is to ensure ACPI (CONFIG_ACPI) is enabled in 
the kernel and that 'acpi=off' is not provided as a kernel command line 
argument.

------------------------------
Copyright (C) 2005 - 2006, Intel Corporation

INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL PRODUCTS.  
EXCEPT AS PROVIDED IN INTEL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, 
INTEL ASSUMES NO LIABILITY WHATSOEVER, AND INTEL DISCLAIMS ANY EXPRESS OR 
IMPLIED WARRANTY RELATING TO SALE AND/OR USE OF INTEL PRODUCTS, INCLUDING 
LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, 
MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT, OR OTHER 
INTELLECTUAL PROPERTY RIGHT. 

This document is subject to change without notice. 

* Other names and brands may be claimed as the property of others.

