Saturday, May 28, 2011

PSB-GFX was the gift from guru Alan Cox and Kristoffer.

From 4Q 2010 to 1Q 2011, I've been working with GMA500 Team. :)
that team is fantastic!!

and early 2011 the Linux-Next Team (they had been developing amazing kernels for a long time!) had released completely new driver for Poulsbo chipsets. it called "PSB-GFX".  the rock Alan Cox developed it. yeah he is god of opensourced Intel drivers... and also Kristoffer had managed Alan's codes to embed git development kernel tree.;a=shortlog;h=refs/heads/v2.6.39-rc1-gma500

So I had been contributing above codes to fit with Ubuntu-kernel as external "dkms". psb_gfx is the real KMS (Kernel Mode Setting) driver to handle framebuffer well. already we had some drivers for poulsbo, but all of them had not implement for such KMS features... for the future, I believe that we must need KMS features to run new born Graphical Window System, especially "Wayland". additionally psb_gfx had some great benefits to take us the higher by incredible 2D accel... :D this accel is similar to generic intel drivers, and also has "GEM" technologies instead of ttm or any other VRAM managements. for 2D rendering speed, it's the fastest driver in ours. today we could run this driver "out of the box" by employing 2.6.39 kernel.


this driver isn't perfect.

  1. because of some lack of dithering in fullscreen, it has ugly color gradations...
  2. acpi_video_register didn't match all of laptops. 

so I've hacked the codes in above issues for Ubuntu... that's the reason why we had remained dkms in our PPA. dkms kernel system would give the more higher priority to external modules, so once you had installed our psb_gfx as dkms, you could avoid the default one safely... ;)

Anyway, this driver would be the baselines of poulsbo for the future... so I gotta fix some remained issues to keep up the support! :D


  1. Agree with you, it was really a great gift!

    I've still some doubts here and there haven't found answers about them (probably it is too early to find them):
    - Will psb-gfx switch from the (amazing fast) framebuffer to a real X driver?
    - Will it include any Xvideo accel in future?
    - Will it receive some love for suspend and backlight control?
    - Anyone said Gallium3D and vaapi, althought not vital? :P

    This great work is a future assurance for poulsbo netbook owners and, why not, also an opportunity for Intel to produce itself better drivers for this chipset!

  2. Hi Luca. :)

    yeah exactly you're right.
    I'm also dreaming such dream like you!

    to get X driver, we would need some help from guru... I'm scratching some "minimum" psb driver for gfx now... :P but still under faults...

    XV would be a bit easier than vaapi I think. but recently fbdev had got rid of some xv features to run stable... so we might salvage some codes from old psb...

    also I start searching some codes in kernelspace to improve suspend/resume.

    ahahaha :D
    that's nice. it might be needed some reverse engineering! ;)

    finally, I also suppose these features would be needed by guys who loves old psb and current emgd... and I really want Intel to join develop such stuff with gma500 team!!