I don't know if it's helpful, but I'm struggling with a similar issue on my
RPi 3 B+, where the official touchscreen, as well as, the HDMI don't output
any graphics, although detected correctly. (See:
https://lists.yoctoproject.org/pipermail/yocto/2019-May/045277.html)
After experimenting with sumo, thud and the latest master recipes, I
remembered a conversation on Andrei's GitHub project (
https://github.com/agherzan/meta-raspberrypi/issues/228), which isn't
exactly related to my issue, but I gave it a try to switch the machine from
"raspberrypi3-64" to "raspberrypi3" in order to get a 32 bit version of the
same build (of master) for core-image-x11.
However, ... this image works for the DSI port, as well as, for the HDMI.

This isn't a real solution, but at least a point to start investigating the
problem and comparing the two builds. Will try to find some time, during
the coming week, to do so, ... although I'm not experienced with the RPis -
maybe I can find something.

Regards,
Bernhard



Am Do., 16. Mai 2019 um 19:34 Uhr schrieb Rudolf J Streif <
rudolf.streif@ibeeto.com>:

> No, unfortunately not. HDMI works just fine but no video on the touch
> display.
>
> On 5/16/19 9:46 AM, Andrei Gherzan wrote:
> > Hi,
> >
> > On 16/05/2019 17.24, Rudolf J Streif wrote:
> >> Thank you, Paul. I did read Andrei's excellent documentation and
> >> enabled I2C and SPI etc.
> > And it didn't work?
> >
> --
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> Rudolf J Streif
> CEO/CTO ibeeto
> +1.855.442.3396 x700
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