Hi all, I am trying to use a pca9535 i2c gpio expander with interrupts on an A10 based board and struggled. I have figured out that the problem is the lack of free virtual/software interrupts as configured in arch/arm/plat-sunxi/include/plat/irqs.h. In that file NR_IRQS is coded as (96+32) which leaves nothing for virtual/software interrupts. All of the GPIO expanders that support interrupts consume one interrupt per gpio pin on the expander (so 16 in my case). NR_IRQS needs to be set 16 higher for the pca953x driver to successfully grab that many interrupts.
What is the best method for configuring/increasing NR_IRQS when using gpio expanders? Note that it is possible to add 8 pca9535 chips to each i2c bus, so just adding 16 if that driver is enabled with interrupts is not an option as it is possible for it to consume 3*16*8=384 interrupts on an A10. Cheers Simon -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
