SPI TFT display problems

Plugging in devices such as LAN adapters, Wi-Fi cards, printers, etc. to Arch Linux ARM.

SPI TFT display problems

Postby keithspg » Tue Oct 20, 2020 9:59 pm

I have my display working but only when I use
Code: Select all
dtoverlay=upstream


It is an adafruit 3.5" spi based display. I am running a Raspberry Pi3 and kernel 5.4.70. I use a dtoverlay of:
Code: Select all
# PItft 3.5" screen
dtparam=spi=on
dtoverlay=pitft35-resistive,rotate=90,speed=32000000,fps=20


This used to work without the 'upstream' and now I must put that in to get a console or for X. In reading about this, it is a compatibility for upstream kernels to work with the 'older' overlays. Where can I find info on the 'current' overlays?
keithspg
 
Posts: 96
Joined: Mon Feb 23, 2015 4:14 pm

Re: SPI TFT display problems

Postby keithspg » Fri Oct 23, 2020 6:27 pm

In case anyone else gets here... I figured it out.

To get the display to work in X, I needed to point my fbdev setup to /dev/fb1 instead of /dev/fb0 in the xorg config
Code: Select all
    ...
    Driver "fbdev"
    Option "fbdev" "/dev/fb1"
    ...


to get the console to show, I had to add 'fbcon=map:10' to /boot/cmdline.txt

it is strange that the dtoverlay=upstream uses fb0 instead of fb1, but at least this works.
keithspg
 
Posts: 96
Joined: Mon Feb 23, 2015 4:14 pm


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