Tobias Kahlki authored Feb 22, 2024 and Tobias Kahlki committed Oct 22, 2024

Reading the input status register resets the interrupt status register.
If an interrupt from the GPIO-Expander to the SoC is issued and an additional
GPIO read occurs at the same time, the GPIO read might reset the interrupt
status register (by reading the input status register). The IRQ routine of
the GPIO-Expander is then unable to determine on which input an interrupt
occurred. To prevent this from happening, the interrupt status register is
read before each read of the input status register and the result is saved
for later processing. In the IRQ routine, the current interrupt status
register value is then combined with the stored value.