The number of interrupts in a domain may be not divisible by the number of interrupts each chip handles. Integer division may truncate the result, thus use DIV_ROUND_UP to count numchips.
Signed-off-by: Axel Lin <[email protected]> --- Seems all users of irq_alloc_domain_generic_chips() in current code do not have this issue. I just found the issue while reading the code. In the commit 02c981c0 of "ARM: CSR: Adding CSR SiRFprimaII board support" It set SIRFSOC_INTENAL_IRQ_END to 59. So I think this might be a possible case for some hardware. kernel/irq/generic-chip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c index 10e663a..452d6f2 100644 --- a/kernel/irq/generic-chip.c +++ b/kernel/irq/generic-chip.c @@ -275,7 +275,7 @@ int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip, if (d->gc) return -EBUSY; - numchips = d->revmap_size / irqs_per_chip; + numchips = DIV_ROUND_UP(d->revmap_size, irqs_per_chip); if (!numchips) return -EINVAL; -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
