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

[Jiang Liu <jiang.liu@linux.intel.com>]

On 2015/7/30 16:33, Thomas Gleixner wrote:
> 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.
You have given me the most valuable hints about the difference in
irq flow handler:)