Re: [PATCH] asm-generic: Raise default NR_IRQS when using sparse IRQs

[Pavel Vasilyev <pavel@pavlinux.ru>]

On 29.11.2010 22:20, Mark Brown wrote:
> Rather than have each platform using sparse IRQs pick a suitably large
> NR_IRQS for use with sparse IRQs make the default high when they are
> enabled.  We pick 64k as there is still a bitmap of IRQs that is
> allocated statically, and as we all know 64k should be enough for
> anyone.
> 
> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
> ---
>  include/asm-generic/irq.h |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
> 
> diff --git a/include/asm-generic/irq.h b/include/asm-generic/irq.h
> index b90ec0b..0d95650 100644
> --- a/include/asm-generic/irq.h
> +++ b/include/asm-generic/irq.h
> @@ -4,11 +4,15 @@
>  /*
>   * NR_IRQS is the upper bound of how many interrupts can be handled
>   * in the platform. It is used to size the static irq_map array,
> - * so don't make it too big.
> + * so don't make it too big unless we're using sparse IRQs.
>   */
>  #ifndef NR_IRQS
> +#ifdef CONFIG_SPARSE_IRQ
> +#define NR_IRQS 0xffff
> +#else
>  #define NR_IRQS 64
>  #endif
> +#endif
>  
>  static inline int irq_canonicalize(int irq)
>  {

May be

  #define NR_IRQS 15*NR_CPUS