Re: [PATCH] irq: Add a new IRQF_ACK_BEFORE_UNMASK irq flag

[Thomas Gleixner]

On Thu, 13 Mar 2014, Sebastian Andrzej Siewior wrote:

> * Thomas Gleixner | 2014-03-12 11:38:24 [+0100]:
> 
> >Untested patch below.
> Tested-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> 
> on DA850 / OMAP-L138. Without:
>   59:        560   cp_intc  ohci_hcd:usb2
> with the patch
>   59:        280   cp_intc  ohci_hcd:usb2
> 
> that makes a difference of 280 interrupts. Prior the patch each
> interrupt was handled twice and returned once with IRQ_HANDLED and the
> second time with IRQ_NONE. With the proper EOI ack I don't see the
> IRQ_NONE anymore.

Right. The documentation of L138 clearly says, that you need to ack
the interrupt AFTER the handler has run. But the driver uses
handle_edge_irq, which acks BEFORE the handler has run.

Quality stuff.

Thanks,

	tglx






--
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/