[ag-automation] Patch for Linux kernel 3.2.0-rc6

[Carsten Emde]

Jens Aksel,

> I am working on a system based on the AM3517 Cortex A8 processor from
> TI (OMAP3). My Linux kernel version is 3.2.0-rc6 and I consider to
> apply the RT patch "patches-3.2.0-rc6-rt9".
You may even use Linux 3.2.2 and patch it witch rt10 
(http://www.kernel.org/pub/linux/kernel/projects/rt/3.2/patches-3.2-rt10.tar.bz2). 
There are just a few offsets to ignore. Several QA farm systems run this 
kernel without any problem so far. You may at any time click on the 
"Kernel version" title line in the Kernels overview 
(https://www.osadl.org/?id=1001) and scroll to the bottom of the table 
where you find the most recent kernel release under test.

> The latest stable RT patch is however only for linux-2.6.33.7
> according to
> https://www.osadl.org/Realtime-Linux.projects-realtime-linux.0.html.
Yes, indeed. We made the (probably naive) promise to not label a kernel 
version "Latest Stable", unless there are no known bugs or regressions. 
Unfortunately, 3.x still has a nasty ACPI problem, some notebooks do not 
enable backlight, many boards require a drm patch to work if no LVDS 
connected, and sockets have longer latencies than in 2.6.33. Several 
issues are already fixed and patches simply need to be sent upstream, 
some issues are known to be solved but actually need to be coded, and 
some other issues are not yet known how to be solved. Fixed but not yet 
mainlined patches are available in the profiles of our QA farm systems; 
there is a section "Off-tree patches" that contains quilt series we used 
to build a particular kernel.

> Could you please explain "how stable" patch patches-3.2-rc6-rt9 is?
Very stable.

> Is this patch considered safe/ready for a production systems?
If you test your system thoroughly and everything works fine, you may 
even use it in a production system. It is, as always, your decision. 
However, OSADL makes special guarantees of a "Latest Stable" kernel for 
its members (such as long-term data collection, support for 
certification, backports etc.) which is not yet available for a 3.x kernel.

> When will a stable patch be released for 3.2.0?
The day when there are no more known bugs or regressions.

Hope this helps,
Carsten.