Re: [Bugfix] x86, irq: Fix regression caused by commit d32932d02e18

[Thomas Gleixner <tglx@linutronix.de>]

On Thu, 30 Jul 2015, Jiang Liu wrote:

> Commit d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical
> irqdomain interfaces") introduced a regression when converting IOAPIC
> to hierarchy irqdomain, which sets wrong irq flow handler for IOAPIC
> pins on Surface Pro 3 and causes failure when detecting I2C controllers.
> It's caused by using stale attribute value when setting up IOAPIC pins.
> With this patch applied, all IOAPIC IRQ configuration are identical
> to v4.1 on Surface Pro 3.
>  
> Fixes: d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
> Reported-by: Matt Fleming <matt@codeblueprint.co.uk>
> Tested-and-reported-by: Chen Yu <yu.c.chen@intel.com>
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> ---
> Hi Matt,
> 	Could you please help to test this patch?
> Thanks!
> Gerry
> ---
>  arch/x86/kernel/apic/io_apic.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index 845dc0df2002..206052e55517 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -943,7 +943,7 @@ static bool mp_check_pin_attr(int irq, struct irq_alloc_info *info)
>  	 */
>  	if (irq < nr_legacy_irqs() && data->count == 1) {
>  		if (info->ioapic_trigger != data->trigger)
> -			mp_register_handler(irq, data->trigger);
> +			mp_register_handler(irq, info->ioapic_trigger);
>  		data->entry.trigger = data->trigger = info->ioapic_trigger;
>  		data->entry.polarity = data->polarity = info->ioapic_polarity;

Pretty obvious, but I was staring at this very piece of code for hours
without spotting it.