Messages in this thread | | | Date | Fri, 20 Jan 2012 09:15:57 -0700 | From | Grant Likely <> | Subject | Re: [PATCH] arm: irq: Allow for specification of no preallocated irqs |
| |
On Thu, Jan 19, 2012 at 04:29:43PM -0800, Michael Bohan wrote: > On 1/19/2012 3:04 PM, Rob Herring wrote: > >No doubt that arch_probe_nr_irqs is doing the wrong thing on ARM, but no > >pre-allocation is not what we want either. We ultimately want > >arch_probe_nr_irqs to return NR_IRQS_LEGACY (16) to reserve IRQ0 (aka > >NO_IRQ) and legacy ISA IRQs. With my series, NR_IRQS is set to > >NR_IRQS_LEGACY for SPARSE_IRQ. You can accomplish the same thing without > >that series by setting .nr_irqs to NR_IRQS for non-DT and to > >NR_IRQS_LEGACY for DT. For platforms to work in single kernel builds, > >they will need to select SPARSE_IRQ. > > One issue here is that IRQ_BITMAP_BITS is defined as a function of > NR_IRQS. Currently, there's a hack in place that arbitrarily tacks > on 8196 bits to the end, giving the max virq supported as 8212 with > your patches. Unfortunately, the system I'm running on will require > higher values than that, so this actually breaks me.
Are that many irqs actually going to be in-use at one time? If not, then the driver should use the irq_domain radix tree reverse map anyway.
g.
| |