When I activate the overlay for the 8HD display (using rsetup) I am no longer able to initialize a number of GPIO pins at /sys/class/gpio. I get a “write error: Device or resource busy” message. I am guessing that the display is using or “making claim” to some of these pins.
Is there documentation somewhere on how the 8 HD overlay impacts the use of the GPIO pins?
Theoretically, it should only affect the GPIOs used by the 8” screen dts, the other GPIOs are not affected.
The Gt911 touchscreen uses 1 pin for INT , some refresh timing issues could loop INT and blob
other resources…
Can you post a dmesg?
look for something like this, it could be a module order problem, but it’s just a guess…
1.513054] pps_core: LinuxPPS API ver. 1 registered
[ 1.518017] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti giometti@linux.it
[ 4.404332] pps-gpio pps: failed to request PPS GPIO
[ 4.409427] pps-gpio: probe of pps failed with error -22