[PATCH 6/6] ARM: gic: use handle_fasteoi_irq for SPIs

[Santosh Shilimkar]

On 4/19/2011 8:46 PM, Will Deacon wrote:
> Hi Santosh,
>
> On Tue, 2011-04-19 at 12:20 +0100, Santosh Shilimkar wrote:
>> On 4/13/2011 12:05 AM, Will Deacon wrote:
>>> Currently, the gic uses handle_level_irq for handling SPIs (Shared
>>> Peripheral Interrupts), requiring active interrupts to be masked at
>>> the distributor level during IRQ handling.
>>>
>>> On a virtualised system, only the CPU interfaces are virtualised in
>>> hardware. Accesses to the distributor must be trapped by the
>>> hypervisor, adding latency to the critical interrupt path in Linux.
>>>
>>> This patch modifies the GIC code to use handle_fasteoi_irq for handling
>>> interrupts, which only requires us to signal EOI to the CPU interface
>>> when handling is complete. Cascaded IRQ handling is also updated to use
>>> the chained IRQ enter/exit functions to honour the flow control of the
>>> parent chip.
>>>
>>> Note that commit 846afbd1 ("GIC: Dont disable INT in ack callback")
>>> broke cascading interrupts by forgetting to add IRQ masking. This is
>>> no longer an issue because the unmask call is now unnecessary.
>>>
>>> Tested on Versatile Express and Realview EB (1176 w/ cascaded GICs).
>>>
>>> Cc: Abhijeet Dharmapurikar<adharmap at codeaurora.org>
>>> Cc: Russell King - ARM Linux<linux at arm.linux.org.uk>
>>> Acked-by: Catalin Marinas<catalin.marinas at arm.com>
>>> Signed-off-by: Will Deacon<will.deacon at arm.com>
>>> ---
>> Tested with OMAP4.
>> Acked-by: Santosh Shilimkar<santosh.shilimkar at ti.com>
>> Tested-by: Santosh Shilimkar<santosh.shilimkar at ti.com>
>
> Cheers for this. I'll add this and the tags for the OMAP-specific patch
> (for some reason you dropped the list when you replied with your Ack).
>
Sure. By mistake I did reply instead of reply all :(

Regards
Santosh