Monthly Archives: June 2011

OLPC weekly update 24/06

I spent most of this week doing release management tasks for OLPC’s upcoming software release, known as 11.2.0. We are now in the final stages. Thanks to all the testing and feedback that has been sent in so far.

Recent university projects

I’m currently studying innovation & entrepreneurship at Manchester Business School, and I’ve recently finished some exciting industry-linked projects.

In one group, we performed a market study of the offshore wind energy generation sector, working in collaboration with Cella Energy. Cella is commercialising a new approach to hydrogen storage which could have great implications on the energy sector in future. Through primary research with various offshore wind companies and industry experts, we identified the key challenges and benefits that would be offered by replacing costy undersea transmission cable’s with Cella’s hydrogen storage technology – just one potential application where this breakthrough could be applied.

In another group, we performed some research for Corporate Finance North West (Funding Enterprise). Through speaking to local small businesses, venture capitalists and business angels, we identified the key challenges associated with Investment Readiness of small firms in the area, and the difficulties in matching the right investor with the right opportunity. We found that there is a high availability of capital in this part of the country, but identified problems within the procedures under which investments are made. A section of our final report has been published by the client.

Thanks to everyone who collaborated on these highly rewarding and engaging projects.

OLPC weekly update 17/06

OLPC weekly update 10/06

This week for OLPC, I’ve been looking at power management of SD cards, as this follows on from some work done last week, working around wireless card firmware bugs by resetting the card. It also falls into part of my work on upstreaming all OLPC’s kernel work.

OLPC’s kernel includes a hacky rfkill driver for power saving, where we use an rfkill interface to cut power to the SD card. This idea was (rightly) criticised by Linux SD/MMC layer developers, who pointed out that it should instead be done with the new SD/MMC runtime power management functionality, which allows driver writers to power on/off the card at will. Our wireless driver (libertas) should just power down the card when the network interface is down.

However, the new runtime power management functionality of the SD/MMC layer doesn’t work with our wireless card. After removing power, it fails to power it on again. With help from upstream I’ve been investigating this, comparing it to our known-working rfkill codepath which could reliably manage power state, and we’re now close to solving this properly.

I’ve also written the appropriate libertas code to perform power management as was suggested, which seems to be working nicely, on top of fixes in the MMC/SD runtime power management layer.


OLPC weekly update 03/06

My work this week:

  • Wrapped up metacity work to allow sugar to correctly implement its Alt-Tab handler
  • Minor updates/fixes to our previous Sugar activity updater for inclusion in 11.2.0 builds
  • Worked around a long-term MediaWiki-squid bug that was interfering with our activity group hosting on the OLPC wiki.
  • Implemented and tested ubifs image signing in olpc-os-builder in preparation for 11.2.0 release
  • Fixed a couple of new bugs with olpc-update versions management (#10929, #10942), hopefully without introducing more bugs!
  • Fixed a new libertas wifi reset issue introduced by the rfkill fix last week
  • Worked around a strange libertas_sdio wifi hardware issue highlighted by a new MMC interrupt handling optimization in the upstream kernel
  • Started investigating a low-level Python crash sometimes triggered by Sugar usage
  • 11.2.0 releases 21/22 and testing