2008-01-13 09:34:14

by Thomas Bächler

[permalink] [raw]
Subject: iwl3945 driver is still unusable!

Some history of this problem can be found here:
http://bughost.org/bugzilla/show_bug.cgi?id=1468

I want to describe my problem here again to get some more people to pay
attention, as Intel doesn't seem to be able to reproduce this problem,
although it is quite easy and I am not the only one who experiences it.

I will start with my setup: I own a Lenovo 3000 N100, which includes a
Core 2 Duo CPU and an Intel 3945ABG Wireless LAN chip. I am working with
Archlinux x86_64 and use wpa_supplicant 0.5.9 (0.5.8 and 0.5.7 in the
past) combined with autowifi, a small tool that starts dhclient
automatically once a wireless connection has been established by
wpa_supplicant.

I am roaming with my Laptop a lot, so I have to switch between networks
often. After I had some problems with the driver over half a year ago, I
figured out this test case:

- Connect to my own WPA network.
- Tell wpa_supplicant to switch to an open network.
- Switch to another open network or (if none available) back to my WPA
network.

The first network I use after loading the driver always works fine.
After some switching networks (always the second or at most third
network I try to connect to), I don't get DHCP anymore. Sometimes I
still get a DHCPNAK, but after that, there is no response to my
DHCPDISCOVER messages. When apppropriate, I assign a static IP and still
cannot transmit any traffic. However, I can always reconnect to the last
working network (so long-term, the driver works with exactly one network).

One of the debug outputs I generated for the bug report (see above)
suggests that only the first package is transmitted over the link, after
that no data is transmitted at all!

This problem persists even if I
- restart wpa_supplicant
- unload the driver and the mac80211 stack completely and reload them
- do both of the above and then suspend to RAM, then resume later and
try again

This issue is not limited to switching between encrypted and unencrypted
networks. I am pretty sure that if I connect to my WPA network here at
home, go to the university and connect to their WPA network, the issue
persists (however, this is not a practical test case, as there is a 30
minute walk in between).

These are the test cases I did today (I could get similar results with
older kernel versions and drivers):

Linux 2.6.23.13, iwlwifi 1.2.23 from Intel's website:
- Connect to WPA network succeeds
- Connect to an open network succeeds
- Going back to the WPA network: Associates fine, but no DHCP, with
static IP no traffic can be transmitted

Linux 2.6.24-rc7-gd0c4c9d4 (latest git as of today), included iwl3945
version:
- Connect to WPA network succeeds
- Connect to an open network: Associates fine, no DHCP (same network
that I could connect to in the last test).

Linux 2.6.24-rc7-gd0c4c9d4 (latest git as of today), iwlwifi 1.2.23:
- Does not compile!

All these test cases _always_ worked perfectly with the old ipw3945
driver. Unloading the iwl driver and loading the ipw driver always makes
my connection work again. BUT, the ipw3945 driver has been discontinued
and does not compile anymore with 2.6.24 (as iwl3945 is considered a
replacement, which it is obviously not).
All this means, if I update to 2.6.24 (which I want to, due to several
improvements), I have no usable driver for my wireless anymore.

What I need is a solution, meaning either a working iwl3945 version or a
patch to ipw3945 to compile with 2.6.24.

Thanks in advance for any help or comments.



2008-01-19 02:04:57

by Jerone Young

[permalink] [raw]
Subject: Re: [ipw3945-devel] iwl3945 driver is still unusable!

If the ipw3945 is no longer going to be maintained. You guys should
consider removing it from the mainline kernel. This is in favor of
iwl3945 (which is in the kernel also).

On Jan 18, 2008 3:09 PM, Chatre, Reinette <[email protected]> w=
rote:
> On Friday, January 18, 2008 12:42 PM, Thomas B=E4chler wrote:
>
> >> ipw3945 is deprecated - we focus our effort on iwlwifi at this tim=
e.
> >
> > Which doesn't help anyone if it does not work. ipw3945 may be
> > deprecated in your eyes, but for me it is the only way to make my
> > wireless NIC work
> > reliably. From my point of view ipw3945 is stable and iwl3945
> > is _alpha_
> > software.
>
> Please understand that we need to focus limited resources. ipw3945 is=
deprecated and we focus on iwlwifi, which supports both 3945 and 4965.=
Unfortunately we have been unable to reproduce your problem.
>
> > It is, but if you read my E-Mail, you will notice that the driver
> > included in 2.6.24 is unusable, thus my request to use a newer driv=
er
> > with a _stable_ kernel. The wireless-dev is based on the latest
> > linux-2.6 git, which is not always stable.
>
> For this purpose I suggest that you consider the compat-wireless proj=
ect. See http://www.kernel.org/pub/scm/linux/kernel/git/mcgrof/compat-w=
ireless-2.6.git and http://linuxwireless.org/download/compat-wireless-2=
=2E6/.
>
>
> Reinette
>
>
> ---------------------------------------------------------------------=
----
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2008.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> _______________________________________________
> Ipw3945-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/ipw3945-devel
>

2008-01-13 10:17:35

by Jerone Young

[permalink] [raw]
Subject: Re: [ipw3945-devel] iwl3945 driver is still unusable!

I have a Thinkpad T61. Though I have a feeling your problem could be
your software combination. For kicks could try Ubuntu 7.10 (even as
just running from a Live CD) and see what happens. I often roam a lot
with my T61, but I do have an Intel 4965 wireless chipset. The Gutsy
Live CD can be found here:
http://www.ubuntu.com/getubuntu/download

I have been using Gnome & Network Manger with WPA2 at home & some
other places without issue (all using DHCP).

Could you try it out and let the list know of the result. You actually
may have found a real bug. Though it seems like other things may be in
the way. So something know nto be somewhat sane and seeing the same
result whould help a lot. So try running the Gutsy Live CD and using
Gnome & Network Manger and see if you see the same results switching
between these networks. This issue could just be the combination of
software you are using...it's worth a shot.

On Jan 13, 2008 3:33 AM, Thomas B=E4chler <[email protected]> wrote:
> Some history of this problem can be found here:
> http://bughost.org/bugzilla/show_bug.cgi?id=3D1468
>
> I want to describe my problem here again to get some more people to p=
ay
> attention, as Intel doesn't seem to be able to reproduce this problem=
,
> although it is quite easy and I am not the only one who experiences i=
t.
>
> I will start with my setup: I own a Lenovo 3000 N100, which includes =
a
> Core 2 Duo CPU and an Intel 3945ABG Wireless LAN chip. I am working w=
ith
> Archlinux x86_64 and use wpa_supplicant 0.5.9 (0.5.8 and 0.5.7 in the
> past) combined with autowifi, a small tool that starts dhclient
> automatically once a wireless connection has been established by
> wpa_supplicant.
>
> I am roaming with my Laptop a lot, so I have to switch between networ=
ks
> often. After I had some problems with the driver over half a year ago=
, I
> figured out this test case:
>
> - Connect to my own WPA network.
> - Tell wpa_supplicant to switch to an open network.
> - Switch to another open network or (if none available) back to my WP=
A
> network.
>
> The first network I use after loading the driver always works fine.
> After some switching networks (always the second or at most third
> network I try to connect to), I don't get DHCP anymore. Sometimes I
> still get a DHCPNAK, but after that, there is no response to my
> DHCPDISCOVER messages. When apppropriate, I assign a static IP and st=
ill
> cannot transmit any traffic. However, I can always reconnect to the l=
ast
> working network (so long-term, the driver works with exactly one netw=
ork).
>
> One of the debug outputs I generated for the bug report (see above)
> suggests that only the first package is transmitted over the link, af=
ter
> that no data is transmitted at all!
>
> This problem persists even if I
> - restart wpa_supplicant
> - unload the driver and the mac80211 stack completely and reload them
> - do both of the above and then suspend to RAM, then resume later and
> try again
>
> This issue is not limited to switching between encrypted and unencryp=
ted
> networks. I am pretty sure that if I connect to my WPA network here a=
t
> home, go to the university and connect to their WPA network, the issu=
e
> persists (however, this is not a practical test case, as there is a 3=
0
> minute walk in between).
>
> These are the test cases I did today (I could get similar results wit=
h
> older kernel versions and drivers):
>
> Linux 2.6.23.13, iwlwifi 1.2.23 from Intel's website:
> - Connect to WPA network succeeds
> - Connect to an open network succeeds
> - Going back to the WPA network: Associates fine, but no DHCP, with
> static IP no traffic can be transmitted
>
> Linux 2.6.24-rc7-gd0c4c9d4 (latest git as of today), included iwl3945
> version:
> - Connect to WPA network succeeds
> - Connect to an open network: Associates fine, no DHCP (same network
> that I could connect to in the last test).
>
> Linux 2.6.24-rc7-gd0c4c9d4 (latest git as of today), iwlwifi 1.2.23:
> - Does not compile!
>
> All these test cases _always_ worked perfectly with the old ipw3945
> driver. Unloading the iwl driver and loading the ipw driver always ma=
kes
> my connection work again. BUT, the ipw3945 driver has been discontinu=
ed
> and does not compile anymore with 2.6.24 (as iwl3945 is considered a
> replacement, which it is obviously not).
> All this means, if I update to 2.6.24 (which I want to, due to severa=
l
> improvements), I have no usable driver for my wireless anymore.
>
> What I need is a solution, meaning either a working iwl3945 version o=
r a
> patch to ipw3945 to compile with 2.6.24.
>
> Thanks in advance for any help or comments.
>
>
> ---------------------------------------------------------------------=
----
> Check out the new SourceForge.net Marketplace.
> It's the best place to buy or sell services for
> just about anything Open Source.
> http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/mark=
etplace
> _______________________________________________
> Ipw3945-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/ipw3945-devel
>

2008-01-18 16:09:48

by Reinette Chatre

[permalink] [raw]
Subject: RE: Re: iwl3945 driver is still unusable!

On , Thomas B=E4chler wrote:

> Thomas B=E4chler schrieb:
>> What I need is a solution, meaning either a working iwl3945 version
>> or a patch to ipw3945 to compile with 2.6.24.
>=20
> I was hoping for someone from Intel or someone with knowledge of the
> code to comment on both these issues:
>=20
> - Can ipw3945 be modified to compile with 2.6.24?

ipw3945 is deprecated - we focus our effort on iwlwifi at this time.

> - Can the newest iwl3945 from the website be modified to compile with
> 2.6.24?

iwlwifi is included in 2.6.24 so you can use it from there. If you are =
interested in the latest iwlwifi development (more recent than what is =
in 2.6.24) then you can work from John Linville's wireless-2.6 (#everyt=
hing) repository.

Reinette

2008-01-18 21:09:45

by Reinette Chatre

[permalink] [raw]
Subject: RE: iwl3945 driver is still unusable!

On Friday, January 18, 2008 12:42 PM, Thomas B=E4chler wrote:

>> ipw3945 is deprecated - we focus our effort on iwlwifi at this time.
>=20
> Which doesn't help anyone if it does not work. ipw3945 may be
> deprecated in your eyes, but for me it is the only way to make my
> wireless NIC work
> reliably. From my point of view ipw3945 is stable and iwl3945
> is _alpha_
> software.

Please understand that we need to focus limited resources. ipw3945 is d=
eprecated and we focus on iwlwifi, which supports both 3945 and 4965. U=
nfortunately we have been unable to reproduce your problem.=20

> It is, but if you read my E-Mail, you will notice that the driver
> included in 2.6.24 is unusable, thus my request to use a newer driver
> with a _stable_ kernel. The wireless-dev is based on the latest
> linux-2.6 git, which is not always stable.

=46or this purpose I suggest that you consider the compat-wireless proj=
ect. See http://www.kernel.org/pub/scm/linux/kernel/git/mcgrof/compat-w=
ireless-2.6.git and http://linuxwireless.org/download/compat-wireless-2=
=2E6/.

Reinette

2008-01-20 10:44:33

by Thomas Bächler

[permalink] [raw]
Subject: Re: iwl3945 driver is still unusable!

Chatre, Reinette schrieb:
>> Which doesn't help anyone if it does not work. ipw3945 may be
>> deprecated in your eyes, but for me it is the only way to make my
>> wireless NIC work
>> reliably. From my point of view ipw3945 is stable and iwl3945
>> is _alpha_
>> software.
>
> Please understand that we need to focus limited resources. ipw3945 is deprecated and we focus on iwlwifi, which supports both 3945 and 4965. Unfortunately we have been unable to reproduce your problem.

Your unability to reproduce the bug is weird, as I can reproduce this
bug every time I try iwl3945, with every version I ever tried and with
every kernel I ever tried. Are there different revisions of the 3945
chip which behave differently and maybe you are trying another one?

[x86_64][11:24:49][thomas@artin ~]$ (lspci; lspci -n)|grep ^03\:00
03:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG
Network Connection (rev 02)
03:00.0 0280: 8086:4227 (rev 02)

Jerone suggested that it may be something in my software (although a
Debian user posted in the bug report that he is also affected, and his
"works for me" comment is based on iwl4965, not 3945). Which components
of my system are inolved here?

- wpa_supplicant: tried versions 0.5.7 to 0.5.9, all the same.
Associating always works (only data transmission after that fails), so
this seems unlikely.
- openssl (which wpa_supplicant depends on): unlikely, as it is only
involved in key negotiation - once the connection has been established,
it does not do anything related to the actual networking.
- glibc: I think I have had more than 5 different versions of glibc
installed since I first saw this bug, so a problem here seems unlikely.
- gcc: It is used to compile linux and the iwlwifi driver, I am
currently using version 4.2.2, I had some 4.1 releases before, all of
them with the same results. May compiling with a different version of
gcc make the bug go away? Which version are you using in your tests?
- linux: tried versions from 2.6.21 (with the Intel mac80211 patch) to
2.6.24, vanilla versions as well as the Archlinux kernel (which includes
some patches), all with the same results.
- the udev firmware loader: if the firmware is not loaded properly, it
may lead to bugs. However, it is simply a script that gives the kernel
the firmware data into sysfs, so if there is a problem here, it is in linux.
- The firmware files: I have these firmware files installed in
/lib/firmware: (with md5sums)
26d10014b09439dc5a8573c2a6f85b0a /lib/firmware/iwlwifi-3945-1.ucode
3afbb112ade3ede3d02e03892ff8a201 /lib/firmware/iwlwifi-3945.ucode
I guess iwlwifi uses the first one now.

So what other problems could there be on my end? When you test your
driver, do you even try if actual data is transmitted after the
association process completed?

I may have time to test this with the Ubuntu Live CD soon (as he
suggested), but I don't think it will make a difference.

I am eager to solve this problem, but I don't know where to look anymore.


Attachments:
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2008-01-18 06:55:27

by Thomas Bächler

[permalink] [raw]
Subject: Re: iwl3945 driver is still unusable!

Thomas B=E4chler schrieb:
> What I need is a solution, meaning either a working iwl3945 version o=
r a
> patch to ipw3945 to compile with 2.6.24.

I was hoping for someone from Intel or someone with knowledge of the
code to comment on both these issues:

- Can ipw3945 be modified to compile with 2.6.24?
- Can the newest iwl3945 from the website be modified to compile with
2.6.24?

2008-01-18 21:13:33

by Thomas Bächler

[permalink] [raw]
Subject: Re: iwl3945 driver is still unusable!

Chatre, Reinette schrieb:
> On , Thomas B?chler wrote:
>
>> Thomas B?chler schrieb:
>>> What I need is a solution, meaning either a working iwl3945 version
>>> or a patch to ipw3945 to compile with 2.6.24.
>> I was hoping for someone from Intel or someone with knowledge of the
>> code to comment on both these issues:
>>
>> - Can ipw3945 be modified to compile with 2.6.24?
>
> ipw3945 is deprecated - we focus our effort on iwlwifi at this time.

Which doesn't help anyone if it does not work. ipw3945 may be deprecated
in your eyes, but for me it is the only way to make my wireless NIC work
reliably. From my point of view ipw3945 is stable and iwl3945 is _alpha_
software.

>> - Can the newest iwl3945 from the website be modified to compile with
>> 2.6.24?
>
> iwlwifi is included in 2.6.24 so you can use it from there. If you are interested in the latest iwlwifi development (more recent than what is in 2.6.24) then you can work from John Linville's wireless-2.6 (#everything) repository.

It is, but if you read my E-Mail, you will notice that the driver
included in 2.6.24 is unusable, thus my request to use a newer driver
with a _stable_ kernel. The wireless-dev is based on the latest
linux-2.6 git, which is not always stable.


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2008-01-19 08:53:50

by drago01

[permalink] [raw]
Subject: Re: [ipw3945-devel] iwl3945 driver is still unusable!

Jerone Young wrote:
> If the ipw3945 is no longer going to be maintained. You guys should
> consider removing it from the mainline kernel. This is in favor of
> iwl3945 (which is in the kernel also).
>
ipw3945 was never in the mainline kernel.
Might be your distro shipping it as an addon.