[Arm-netbook] CT-PC89E kernel 2.6.24.7 source investigation

[Frans Pop]

On Thursday 04 March 2010, Luke Kenneth Casson Leighton wrote:
> 1) frans, i worked out a better (easier) way, which is very very
> simple: move or remove datang-epc.tar.gz from the firmware flashing SD
> card, _but_ place a replacement kernel on it, zImage_dt.  press-hold
> both mouse-buttons; u-boot and then the (new) kernel is copied to the
> NAND flash, and then the search for datang-epc.tar.gz fails, and
> everything stops.  voila.  reboot.  new kernel runs.  repeat.

Hmm, but earlier you said very convincingly that partial firmware upgrades 
were not possible... That was exactly what I was thinking of. :-)

> 2) i noticed the tell-tale sign "S3C_LCD got initialized: 180mhz" and
> started looking on google for this.  up came the SmartQ5 MID device.
> downloaded the source code which was a 2.6.24.7 kernel aaaand bingo,
> the subdirectory drivers/video/s3c/ is missing from 2.6.33 stable.
> so, that's what we need.

I assume you mean:
http://gitorious.org/mer-smartq/mer-smartq-kernel
And in particular commit 9b25305 "Apply samsung kernel patch".

I've added that repo as a remote branch to my local git checkout of the 
upstream kernel and taken a look at it. It's your typical completely 
clueless commit from hardware vendors. It's an aggregated patch including 
fixes and new hardware support and even two binary files. But probably 
they were given it that way by Samsung.

But it does indeed look as if ChiTech have used that same patch as their 
basis (only on top of .24.2, not .24.7; the included changelog suggests 
it's intended for .24.2).

AFAICT the video support added there in that video/s3c directory is an 
extension to the s3c-fb support already present in the standard .24 
and .33 kernels (and which I had enabled).

I've uploaded the patch (without the binary blobs) and a diffstat here:
http://people.debian.org/~fjp/tmp/CT-PC89E/samsung_2.6.24.2.patch.gz
http://people.debian.org/~fjp/tmp/CT-PC89E/samsung_2.6.24.2.diffstat

On Friday 05 March 2010, Luke Kenneth Casson Leighton wrote:
> CT-PC89E - LCD screen is B089AW01 v.1

That looks to be a fairly standard LCD screen which is used in quite a few 
devices already supported by Linux (incl. some Eeepc models).

I also had a look around and found the following possibly useful links:
http://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/index.html
http://git.fluff.org/gitweb?p=bjdooks/linux.git;a=summary

Ben Dooks seems to be the upstream coordinator for Samsung stuff, but 
possibly more intersting, Mark Brown (DD!) is a frequent contributor.

How about asking either of them for suggestions? Maybe they know more about 
the status of that "samsung kernel patch", or have suggestions about 
the "proper" way to get this LCD going with .33.

Cheers,
FJP