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

From: Thomas Gleixner
Date: Thu Jul 30 2015 - 04:34:28 EST


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@xxxxxxxxxxxxxxxxxxx>
> Tested-and-reported-by: Chen Yu <yu.c.chen@xxxxxxxxx>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
> ---
> 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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/