Re: Uses of Linux backports in the industry

[Enrico Weigelt, metux IT consult]

Am 24.06.2015 um 11:19 schrieb Richard Weinberger:

Hi,

> Porting PREEMPT_RT is not that easy.
> Did you ever?

I know.

OTOH, is backporting drivers to ancient kernels (where internal APIs
often are _completely_ different) really easier ? Perhaps it might look
so, if it's just one individual driver - but often it doesn't keep this
way, sooner or later other things pop up.

> So, you rewrite all drivers and the board support from scratch?

Sometimes, if I have to. Because - on my own experience - what SoC
vendors provide usually is pretty unusable, just a quick showcase.

Right now, I'm working on a project w/ some imx53-based board.
What freescale provides here is practically unusable. Really ancient
(last time I checked, it was an old 2.6.x), unsable and insecure
(anybody had a closer look at their "kgsl" patch or their gst-plugin ?)

We'll have to drop the whole idea of using the GPUs, due to lack of
support - the existing driver/libgl is known to be broken and insecure,
no support from fsl whatsoever, we're lacking resources for a full
reverse engineering, and moving to another SoC is out of question
(at least for the forseeable future). So, it ends up in having no
GPU, therefore no GL/GSL, therefore no QtQuick/QML.


Pavel already mentioned the correct way to go: chip vendors should
provide proper (mainline'able) patches, or at least full specs.

And I'll add: those who dont, should simply be boycotted.


cu
--
Enrico Weigelt, metux IT consult
+49-151-27565287
MELAG Medizintechnik oHG Sitz Berlin Registergericht AG Charlottenburg HRA 21333 B

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