Re: Legacy PCI interrupt support in PCIe host driver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, 16 Mar 2017, Mason wrote:
> About shared ISRs. Are they supposed to return IRQ_HANDLED
> if and only if they handled something?

Every interrupt handler is supposed to return IRQ_NONE if it did not handle
it. That does not depend on shared or not. The handler does not know if
it's on a shared interrupt line or not. IRQF_SHARED only tells, that the
handler is capable of sharing the interrupt line with another device.

> Will that stop the next ISR from being called?

No.

> I guess if two interrupts fire at the same time, we'll just take two
> separate exceptions?

Wrong guess. That might work with level interupts, but with other types
nothing will raise another exception. Sharing interrupts on edge types is a
stupid idea, but hardware folks insist on implementing stupid ideas.

Thanks,

	tglx



[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux