Am 24.06.2015 um 11:55 schrieb 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. At the end of the day customers will do what is less costly. Sometimes backporting a driver is much less effort. That's why we have the excellent backports project. >> 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. Sure, in a perfect world. But as of now we have to deal with that. Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe backports" in
