OLPC:News

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Laptop News 2007-07-21

1. Testing: We ran battery-life tests on 75 B4 laptops: results will be reported on the OLPC wiki this week. Next week we will use 100 B4's for mesh tests. Dafydd Harries and Simon McVittie of Collabora will be helping us with mesh-scaling and connectivity tests. The current software builds are progressing well. Most of the Trial-2 features are in Builds 528+; many activities (Read, Write, Chat, Connect4, Record) now have collaboration features enabled; the Journal is integrated, and small link-local mesh networks are working. Thanks to everyone who has been documenting, reviewing, and prioritizing bugs in Trac (http://dev.laptop.org); most have been triaged and will be fixed in the next release (Trial-3).

2. Trial-3: We've started discussions on the software release that will line up with the mass-production hardware build; it needs to be ready in early to mid September. This will be largely based on Trial-2 and will include many bug fixes and only small feature changes.

3. Sugar: Marco Gritti reports “really good progress!” He has chased down numerous bugs—in the clipboard, regarding themes, palette behavior, and the user interface (UI). He has completed much of work of integrating open hardware management (OHM) with the UI. Other details include reworking the brightness and volume key handling for the B3/B4 keyboards; tracking down the “white row” X11 bug; and getting the Totem media plug-in to work in the browser. Tomeu Vizoso also made fixes to the Clipboard; he integrated recent changes in the datastore into Sugar; implemented lazy (paged) scrolling in the Journal by caching more entries than can be shown on-screen and fetching them opportunistically; and fixed some Sugar and Activity file leaks in /tmp.

J.M. Maurer added a “zoom” signal to the libabiword widget, and hook it up in Write; added full justification to the Write activity; implement “buddy left” in Write and the AbiCollab Sugar back end; and he fixed a bug that was causing Write to crash when opening a second instance.

Arjun Sarwal worked further on optimizing the response time of the Measure activity (which turns the laptop into an oscilloscope). He has made improvements to the UI by adding a grid onto the background and he has chosen color scheme that improves contrast. New features include being able to start/stop the display and taking a snapshot of the currently displayed waveform. Data logging has also added. A version of the activity is available at the git repository under the category projects/measure (See Measure / Oscilloscope).

4. GNOME Mobile: John Palmieri was at GUADEC (GNOME Users' And Developers' European Conference) this week, representing OLPC at the GNOME mobile and embedded (GMAE) meeting. The GNOME Mobile platform is a subset of the GNOME platform; it represents components that are currently shipping in the XO, the OpenMoko, the Nokia 800, and other devices.

5. Salut/Gabble: John was joined at GUADEC by Sjoerd Simons, Guillaume Desmottes, Morgan Collett, and Simon McVittie. Between sessions they they worked on minor bug-fixes and updates in Salut (link-local XMPP connection manager). Sjoerd figured out why Salut sometimes “looses” contacts on bad networks. Together, they finished the new tubes specification. Simon also worked on fixing avatar (buddy picture) bugs in Gabble (the Jabber/XMPP connection manager we use for chat and video calls).

6. Builds: Dan Winship cranked out multiple builds per day this week. (We are now up to Build 528.) He made a fix to Pilgrim to accommodate activities with spaces in their names; and he wrote some tools to help determine (and document) changes between builds.

7. Mesh activities: Dan Williams debugged and fix various activity sharing and Mesh View bugs. He fixed Python 2.5 issue that broke sharing in Record and Read; and he wrote a Jukebox activity, a gstreamer-based media player with Journal integration. He also did some Libertas maintenance, patch review; made wireless scans “less hacky”; and fixed a wireless scanning issue in NetworkManager that caused access points to drop off the mesh view over time.

8. Power measurement: This week saw a flurry of activity trying to reconcile the power draw of each XO subsystem with what we expected. John Watlington, Richard Smith, Joel Stanley and Jim Gettys working on detailed analyses of power consumption. The goal of the measurements has been verification we have hardware in place enabling us to turn off any component at will and that an “off” component really is powered off. This will mean that as software development progresses, we will be able to keep any unused circuitry off or at low power when it is unused. We now have 29 different measurement points on the XO, giving us fine- grained data on every power rail, covering all major subsystems.

If all subsystems are on and running at maximum power use, the XO can consume a maximum of approximately six watts (ignoring external USB devices). To verify this, we have put the XO in various states of display, wireless, USB and CPU usage. Normal usage when the system is idle, or in ebook suspend mode, or mesh only mode is very much less than this maximum, of course.

The wattage drawn from each power rail was carefully reviewed and audited to make sure we knew where each watt was going. We were not able to account for every watt of the system, but we are really close—close enough that we feel that all the components are functioning as specified. But “as specified” in a few cases it still a bit high. WLAN and DCON (display controller) are a bit problematic. We have promises from the WLAN team that there are lots of knobs to tweak to reduce power consumption and that they will now start tuning those.

The word from HiMax on DCON though is that what they measure for sleep-mode power draw is the same as what we measured for sleep mode, approximately 150mW. This is not acceptable. When we go into sleep mode or low-power WLAN-only mode we will need to drop the power to the DCON. This means that the kernel will soon have to sprout knowledge of how to init the DCON from power up. Previously the kernel could rely on OpenFirmware (OFW) to have initialized the DCON. (We have verified under OFW that we can drop power to the DCON and then bring it back to life.

Most other Linux power-management controls has been verified as now working correctly, e.g., audio, camera, etc. The surprise discovery is that our processor's power supply is not as efficient as it could be. On the more positive side, we shaved 30mW from the power required when the laptop is not turned off and another 35mW whenever the screen is turned on.

9. Performance: Chris Ball changed some of our power behavior; we now turn off the screen while suspended via the power button or lid close, saving power. Chris noticed that resume from suspend becomes unstable if we are stressing the wireless radio at the time of resume. This bug has been passed on to Marcelo and Cozybit for investigation. Chris also reported a problem with game keys and power management events being seen as power-button presses to AMD; this is putting us into suspend when we don't expect to be going there.

Chris is investigating our memory use, which has crept up recently—we are running more Python processes than we use to without having them share libraries, and running a greedy DHCP server (taking 12–20MB!)

Chris and Richard wrote a Python script to calculate the watt-hour value reached by the battery tests we are doing. This lets us make accurate calculations on the duration we'll get from measured power draws.

10. Firmware: Quanta released the 2nd test for what will turn out to be the PQ2C20 firmware. Richard Smith reviewed all the changes. The highlight feature of this is the removal of code supporting Atest (dropping ATest code removed 672 lines from the code base.)

Andres Salomon worked on a number of embedded controller (EC) fixes, including helping Richard debug EC issues by providing proper kernel support. Mitch Bradley got Forth running on the 8051 processor as a possible base for the open EC code and worked on a firmware release with activation support.

Lilian Walter got IPv4 and IPv6 dual stack ping and finger working. Lilian is researching on how to implement Teredo tunneling (Teredo tunneling is a protocol designed to grant IPv6 connectivity to nodes that are located behind IPv6-unaware NAT devices); this involves Ipv6 features such as router solicitation/advertisement and DNS AAAA packets.

James Cameron has started work on an open-source firmware implementation for the EC.

11. Kernel: Marcelo Tosatti did more parallel suspend/resume testing; found an unnecessary call to mdelay() in the CAFE driver; and investigated more Libertas suspend/resume problems and failures under high traffic. Andres Salomon worked on another Libertas merge, dealt with getting code upstream, got the wakeup-from-keyboard work properly: lots of fixed bugs and hopefully fewer introduced ones..

Remaining for completion of Linux kernel power management is powering the DCON down when not in use (saving 150mw in suspend, as noted above), and debugging of the DCON patch to enable the use of the DCON use when the window system is idle (saving more than 0.25 watts while running). We also need to explore how much power is saved by turning off the Dotclock PLL in the processor when it is not needed. These will improve further our battery life.

12. School server: Daniel Wyatt made the first installing, pre-configured school-server live image (See xs-dev.laptop.org/xs and the scripts in the git tree http://dev.laptop.org/git.do?p=projects/livecd-data;a=summary ; the configuration files are at http://dev.laptop.org/git.do?p=projects/xs-config;a=summary and the XS “call home” scripts are packaged at http://dev.laptop.org/git.do?p=projects/xs-callhome;a=summary).

13. Content bundles: With input from the community, Lauren Klein and Kathy Paur helped flesh out the content-bundle specification. Now we need to implement a mime-type hook for .xol (the extension name being considered) and a script to unpack it and regenerate a navigation templates in /home/olpc/Library. We have had some community members already uploading .xol files to the Library grid on the OLPC wiki.

14. Content Jams: CC-Taiwan is one of the largest Creative Commons chapters; and they are very excited about running a content jam around Wikimania. Another Jam is being planned around linuxconf.au.

More News

Laptop News is archived at Laptop News. Also on community-news.

You can subscribe to the OLPC community-news mailing list by visiting the laptop.org mailman site.

Press requests: please send email to press@racepointgroup.com

Milestones

Latest milestones:

Nov. 2007 Mass Production has started.
July. 2007 One Laptop per Child Announces Final Beta Version of its Revolutionary XO Laptop.
Apr. 2007 First pre-B3 machines built.
Mar. 2007 First mesh network deployment.
Feb. 2007 B2-test machines become available and are shipped to developers and the launch countries.
Jan. 2007 Rwanda announced its participation in the project.

All milestones can be found here.


Press

  1. redirect OLPC:News#Press

More articles can be found here.

Video

Miscellaneous videos of the laptop can be found here.

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