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zvivered 10-17-2012 04:06 AM

vanilla 3.5: Text display turns off every few seconds
Dear Members,

I'm running Vanilla 3.5 with busybox on a Core2Duo PC104.
The kernel + busybox were built using toolchain built with crosstool-ng.

I'm not running any x server. Text only.

Upon boot completion linux runs busybox' rcS that is currently empty.

Every few seconds the display turns black and after ~1sec the text is displayed again.

The kernel was compiled with 'defconfig'.
Should I change something in kernel configuration ?


elucches 10-31-2012 07:41 PM

Have you solved it?

zvivered 11-01-2012 01:28 AM


I did not find a sloution yet.

Linux can fix (I booted with ubunto and knoppix and there is no flickering).

But linux does not cause the problem.

I noticed that the flickering happens when grub is running or under DOS.

I saw the problem in another embedded module (Com express type2) based on CoreI7


zvivered 11-11-2012 03:06 PM

knoppix: nodrm cause flickering

Currently I only have a clue, not a solution.
When I booted the module with Knoppix 7.0.4 with 'knoppix 2 nodrm' the flickering remains.
with 'knoppix 2' the flickering does not exist.

I have to find out what does knoppix with this parameter.


elucches 11-12-2012 07:32 AM

I've never used Knoppix. I just read knoppix-cheatcodes.txt; nodrm means don't load graphics acceleration modules. Guess by now you already found out.
Best regards,

zvivered 11-15-2012 03:08 PM

Solution: Check CONFIG_DRM_I915_KMS
Dear Members,

I checked CONFIG_DRM_I915_KMS (CONFIG_DRM_I915 was already checked) and built the kernel.
This the only change I had to do on defconfig (ARCH=x86)

Upon boot completion there is no flickering.
4 Pingouins are displayed at the top of the screen.
The resolution is higher than 80x25

Not sure this is an optimal solution. According to the help:

Choose this option if you want kernel modesetting enabled by default,
and you have a new enough userspace to support this. Running old
userspaces with this enabled will cause pain. Note that this causes
the driver to bind to PCI devices, which precludes loading things
like intelfb.


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