On Tue, Feb 28, 2012 at 02:10:09PM +0100, Cousson, Benoit wrote: > The following commit: 2f31b51659c2d8315ea2888ba5b93076febe672b > Author: Tero Kristo <t-kristo@xxxxxx> > Date: Fri Dec 16 14:37:00 2011 -0700 > > ARM: OMAP4: PRM: use PRCM interrupt handler > > introduced the PRCM interrupt handler and thus the need > for 64 more interrupts. Since SPARSE_IRQ is still not fully > functional on OMAP, the NR_IRQS needs to be updated to avoid > the failure that happen during irq_alloc_descs call inside > the PRCM driver: > > [ 0.208221] PRCM: failed to allocate irq descs: -12 > > Later the mux framework is then unable to request an IRQ from > the PRCM interrupt handler. > > [ 1.802795] mux: Failed to setup hwmod io irq -22 This is fine for rc, but longer term... Do any of these have hard-coded interrupt numbers associated with them? If not, just enabling sparse IRQ will sort this out. As I tried to explain yesterday, there are two modes for IRQ allocation: 1. Without sparse IRQ enabled, irq_alloc_descs(-1, from, num, -1) will allocate IRQs _within_ the existing from..NR_IRQS range, and will fail if there is insufficient IRQs available. 2. With sparse IRQs enabled, irq_alloc_descs(-1, from, num, -1) will allocate IRQs starting at max(from, NR_IRQS) and working upwards. In either case, irq_alloc_descs(start, 0, num, -1) will allocate 'num' IRQs at 'start' or fail if the range is already in use (and 0..NR_IRQS is defined as 'being in use' when sparse IRQs are enabled.) So, if the PRCM interrupts aren't statically assigned (the code suggests that they aren't) then it's already sparse-IRQ compliant, and enabling sparse IRQ support will mean that they will be allocated above NR_IRQS. Therefore, I suggest rather than raising NR_IRQS, you instead enable SPARSE_IRQ now so that anyone using the dynamic IRQ allocation can benefit from sparse IRQ support without having to have a large NR_IRQS. So, you don't have to wait until everything is converted to use sparse IRQ. You just need to make sure that nothing uses irq_alloc_descs(start, from, num, ...) where start < NR_IRQS, and nothing using that requires statically defined IRQ numbering. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
