On Mon, Jul 9, 2018 at 10:27 AM Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> wrote: > > Sorry for not getting back to you in a timely manner Evan, I wanted to > read up more on the details of how this is supposed to work. I still > haven't done so, but here's my concern: > > When we power down the SoC we're no longer powering either the TLMM or > the GIC, so the MPM or PDC is used to waking the system on some set of > triggers. As such set_wake on an individual pin or irq should be routed > to the MPM/PDC driver, which (in the PDC case) is implemented using > hierarchical irq domains. > > As such I think that we shouldn't toggle the wake property of the > summary pin at all; i.e. the patch should remove that call rather than > propagating what I believe is a constant failure. > > Regards, > Bjorn Hi Bjorn, That's okay, I always feel bad pinging. Thanks for the thoughtful response. Stephen and I are starting to think about how wake interrupts should work with regard to the PDC, and we're at a place where we're a bit unsure of the path forward. Our understanding is the downstream kernel had an interrupt hierarchy of GIC > PDC > TLMM & everybody else. In the downstream world PDC acted transparently, forwarding most requests directly onto the GIC, but quietly handling wake interrupts as well. With the upstream PDC driver, the #interrupt-cells got changed to 2, and it seemed like folks didn't like the idea that PDC was acting transparently. Correct me if I'm wrong there. So now we're sort of unsure about how to wire in PDC. If we make everybody an interrupt child of PDC, then we lose the ability to specify the third GIC parameter, and we're stuck expressing interrupts with respect to PDC pins, which is an awkward mental translation. In this world, does TLMM need to do direct-connect stuff to get wake-able GPIO interrupts working? It would kind of have a foot in both worlds, with its summary interrupt as a GIC interrupt but the wakeable ones as parented by PDC? So anyway, with regard to this patch, I'm happy to create a second spin that simply removes this function, but for me at least it brought up some larger questions we've been wrestling with. -Evan -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
