Re: [Xen-devel] [PATCH] xen/arm: gic_shutdown_irq must only disable the right IRQ

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Fri, 2013-06-28 at 12:25 +0100, Julien Grall wrote:
> When GICD_ICENABLERn is read, all the 1s bit represent enabled IRQs.
> Currently gic_shutdown_irq:
>     - read GICD_ICENABLER
>     - set the corresping bit to 1
>     - write back the new value
> That means, Xen will disable more IRQs than necessary.
> 
> Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>

Doh!

Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>

> ---
>  xen/arch/arm/gic.c |    4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
> index 177560e..cafb681 100644
> --- a/xen/arch/arm/gic.c
> +++ b/xen/arch/arm/gic.c
> @@ -117,12 +117,10 @@ static unsigned int gic_irq_startup(struct irq_desc 
> *desc)
>  
>  static void gic_irq_shutdown(struct irq_desc *desc)
>  {
> -    uint32_t enabler;
>      int irq = desc->irq;
>  
>      /* Disable routing */
> -    enabler = GICD[GICD_ICENABLER + irq / 32];
> -    GICD[GICD_ICENABLER + irq / 32] = enabler | (1u << (irq % 32));
> +    GICD[GICD_ICENABLER + irq / 32] = (1u << (irq % 32));
>  }
>  
>  static void gic_irq_enable(struct irq_desc *desc)



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