Just a quick reminder regarding the gentoo-sources patching policy:

If you have some new hardware which is currently not supported by gentoo-sources, but you know of drivers or patches in the upstream development kernel to support such hardware, you are encouraged to file a bug and we will consider backporting the patch to the current release kernels.

An ideal bug report would look something like:

I recently purchased a Fritzomatic E2 which is not supported by the current gentoo-sources (tested both stable and testing). However, the upstream 2.6.23-rc kernel tree does contain a patch to support this hardware. I applied this patch to 2.6.22 and it works great. Here’s a link to the patch: http://foo. Please consider for upcoming gentoo-sources releases.

Even if you aren’t able to initially go into such detail, you should file a bug anyway.

While we won’t proactively go out adding new hardware support to kernels, if such patches are requested and tested by Gentoo users, we’ll add them provided that they don’t show immediate risk of increased maintenance burden.

Since the Atheros acquisition, introduction of new ZyDAS ZD1211 USB-wireless devices has been concerningly slow.

Fortunately, some new ZD1211 devices have been popping up recently, based on new radio chips. After some help from the community, I managed to get my hands on the new types and write zd1211rw code needed to support these chips.

The first new chip, the AL2230S, only needed a few changes on top of the older AL2230 code. This radio is working well.

The second new chip is especially interesting: the Ubec UW2453. Ubec publish full technical specs for this chip, so we’re able to understand more than usual about the ZD1211 interactions with the radio. Maybe due to it’s complexity, the UW2453 isn’t performing quite as well as the other radios, but this should improve after time. I emailed ZyDAS some feedback about their UW2453 programming code – I think I spotted a few mistakes.

Third, we started seeing the already-supported AL7230B RF chip being combined with the ZD1211B base chip on some newer ZyXEL products. This particular combination was not supported before, but thanks to some testers on the mailing lists, the code has been written and submitted to support these.

Fourth, Atheros appear to have rebranded the ZD1211B chip as AR5007UG. These devices are appearing in Medion laptops, very popular in some parts of Europe. The first ones seem to be based on the UW2453 RF mentioned above. I’m especially interested to hear from people who have AR5007UG devices in other laptops or in standalone USB-dongle form, and also if they exist based on other RF chips.

All the above will be available in Linux 2.6.22, except UW2453/AR5007UG which will be available in 2.6.23.

On a final note, I moved the zd1211rw homepage to the new linuxwireless.org wiki. One nice feature here is that the zd1211rw supported devices list gets aggregated onto the more general Linux-supported USB wireless devices list, however we’re the only USB driver with device information published there at the moment.

ketchup is a neat utility to download and unpack a specific version of the Linux kernel sources into the current directory. It also does rather well on saving download bandwidth, i.e. if you have the 2.6.17 source tarball and ask for 2.6.18, it will only download the 2.6.17-to-2.6.18 patch.

Here’s a quick usage example, which installs the 2.6.21-rc7 kernel sources:

# emerge ketchup
# cd /usr/src
# mkdir linux-2.6.21-rc7
# cd linux-2.6.21-rc7
# ketchup 2.6.21-rc7

When ketchup has finished, you then have a clean set of kernel sources for that particular version in front of you.

I like to configure ketchup to use the same storage directory as portage, so that they can share kernel tarballs. In my ~/.ketchuprc I have:

archive = "/usr/portage/distfiles"

Earlier this month, I met with 25 other contributors at the 2nd Linux Wireless Summit. This was a followup from the 2006 summit.

The meeting happened in London and was scheduled to occur immediately after the IEEE 802.11 working group meeting. This enabled us to get some kind of vendor attendance.

While we had this opportunity, one of the biggest topics was discussion of why vendors still aren’t playing nice in releasing open source drivers (or providing the resources to let the community do so). The vendors in the room confirmed our suspicions – vendors are afraid of the FCC and other regulatory agencies who place restrictions on frequencies and power levels which these devices are legally allowed to transmit as.

Matt Norwood from the Software Freedom Law Center was in attendance and had studied the FCC regulations in some detail. The conclusion is that the FCC rules are vague and while they don’t explicitly say that open source drivers are not allowed, vendors are not prepared to risk falling out of compliance and are playing it safe (or not playing at all). Unfortunately there is no short term solution to this: it would take years for the FCC to clarify the regulations. Short term workarounds such as finding ways to encourage vendors to produce open drivers with only the regulatory part closed (such as Intel’s ipw3945 offering) are under investigation.

The other large topic was the merge of the new wireless stack (d80211) which was donated to the community by Devicescape. The stack has many more features than the current in-kernel ieee80211/softmac stack, and improves consistency between drivers. We are now much closer to getting d80211 merged into mainline Linux, but there are still some significant technical issues to be resolved.

Before the conference, several people asked me if I could raise issues with the suckiness of Intel’s ipw3945 driver offering in that it relies on this awkward closed-source userspace daemon. Fortunately Intel have found a way to rewrite their firmware so that the regulatory domain control is no longer at the driver level, therefore a fully open-source driver with no binary userspace part has been developed (iwlwifi). Although Intel have not yet announced it, the source code has been released here. This rewritten driver uses the d80211 stack mentioned above, so it’s not possible just to compile it against mainline Linux at the moment. The iwlwifi website includes instructions for how to check out the wireless-dev tree where d80211 is being held.

All slides and notes from the conference can be found here. Stephen Hemminger wrote a more detailed summary. Also, one other significant product of the summit was a central information source aimed at Linux wireless users – we have now launched linuxwireless.org.

Despite not mentioning it here for a while, Ulrich Kunitz and myself have been driving forward with our ZD1211 USB-WLAN driver rewrite.

For a start, the driver is included in the recently released Linux 2.6.18 kernel, which has resulted in a drastic increase in the number of users. If you’re looking for a handy way to add wireless connectivity to a computer now and then, these devices are ideal: cheap, small, reliable, in-kernel driver, redistributable firmware.

A more functional driver can be found in the 2.6.19-rc development tree. New features include:

• LED support – the light goes blinky blink during network usage.
• Support for devices based on the AL7230B RF (i.e. ZD1211-based devices which support 802.11a). We don’t support 802.11a connectivity just yet, but you can now use these devices to connect to b/g networks.
• Out-of-the-box support for driverless devices (not even the vendor driver supports this!).
• More accurate signal strength/quality statistics.
• Many more device ID’s added thanks to people testing the driver with their hardware.

Coming for 2.6.20: ERP handling (to play nicer when 802.11b clients are in sight), hardware decryption, and more! Many thanks to ZyDAtheros for their continued support.

I think some people might have misunderstood Diego’s post about ALSA support in Gentoo.

To clarify, we (as in Gentoo kernel maintainers) do support in-kernel ALSA drivers, but Diego (who maintains the out-of-kernel alsa-driver package) does not. I recommend using the in-kernel drivers, Diego recommends using the out-of-kernel drivers.

If you do have problems with the in-kernel version, please do file bugs, but make sure they get assigned to kernel@gentoo.org rather than Diego.

Our driver for USB-WLAN devices based on the ZD1211 chip has progressed through the chain of Linux networking development trees and is now included in the mainline kernel, as of 2.6.18-rc1. I have added the accompanying firmware package to Portage as net-wireless/zd1211-firmware.

We are still developing in out-of-tree git repositories, but I am feeding patches to the in-kernel version which will be sent to Linus during the appropriate merge windows.

Ulrich is AWOL at the moment, probably due to post-World-Cup-depression, but I’m getting back towards actual driver development after some surgery on the softmac layer. Hopefully the minor instability issues will be fixed soon.

We have made a lot of progress since my last post about our rewritten ZD1211 USB-WLAN driver.

• Monitor mode – the ability to spy on local network traffic with tools like ethereal.
• Software encryption – we can now connect to encrypted (WEP + WPA) networks. Hardware-based encryption will be supported later.
• ZD1211B support – we now support the newer range of ZyDAS devices
• Improved RX performance
• Misc fixes and improvements

I managed to get in contact with some ZyDAS engineers, who are responsive and helpful via email. Thumbs up to them, I hope this level of communication can continue for future products beyond the Atheros acquisition.

I have been spending time hacking on softmac (generic code layer which powers ZD1211, bcm43xx, and a few other drivers). I fixed a few bugs, and am now working on finishing some of the incomplete functionality (such as shared key authentication, mixed mode protection and short/long preambles).

There is only one more thing we need to complete before we submit a basic driver for inclusion in Linux 2.6.18: automatic TX power calibration, so that we aren’t needlessly broadcasting our traffic over long distances when the access point is very close. This won’t be too hard once we have figured out how to decode the signal strength. The code in the vendor driver for doing this is quite cryptic, to say the least.

Jonathan Corbet of LWN attended the Linux Wireless Summit and produced a detailed report of the event, which is now public: The 2006 Wireless Networking Summit. It’s an interesting read for anyone who has had the joy of setting up wireless networking on Linux.

Johannes Berg has produced a faces-to-names version of the group photo. Click on a face to see who it is.

I just announced our just-about-functional rewritten ZD1211 driver on the zd1211-devs mailing list. The driver is actually usable (and reliable!) on unencrypted networks.

A fully usable (WLAN client) driver is now well within sight, we just need to implement connecting to encrypted networks and automatic rate management.

More advanced features (such as ad-hoc connectivity, master mode, monitor mode, …) will come later. Hopefully the community will help us out there.