[Patch V1 0/6] Refine generic/PCI MSI irqodmian interfaces

Marc Zyngier marc.zyngier at arm.com
Fri Nov 14 08:03:41 PST 2014

On 14/11/14 15:25, Jiang Liu wrote:
> On 2014/11/14 23:16, Marc Zyngier wrote:
>> On 14/11/14 14:26, Jiang Liu wrote:
>>> On 2014/11/14 22:11, Yijing Wang wrote:
>>> We have achieved 1 and 2. And seems we could also achieve 3 by
>>> converting all arch specific PCI MSI code to use hierarchy
>>> irqdomain. But not sure whether we could achieve 4, not familiar
>>> with ARM world:)
>> Killing all the weak functions shouldn't be a problem for ARM, we're
>> trying very hard not to rely on them.
>> Killing msi_chip is a different story, as this is what we use to match a
>> PCI host controller with its MSI controller (that's what the of_node
>> field in msi_chip is for). See drivers/of/of_pci.c for details.
>> Also, we use msi_chip directly in the MSI drivers as a way to go from a
>> pci_dev to the MSI controller specific structure:
>> http://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/tree/drivers/irqchip/irq-gic-v3-its.c?h=irq/stacked-its-v2#n1143
>> If we're going to kill msi_chip, we must make sure we have mechanisms
>> that allow the conversion of the existing code.
> Hi Marc,
> 	Seem it doesn't worth the effort to remove irq_chip,
> so I will focus on killing all weak functions first:)
> After that, we may kill setup_irq and teardown_irq in irq_chip,
> but seems irq_chip still has other usages, so I won't try to
> kill irq_chip.

I assume you mean msi_chip! ;-)

Killing setup/teardown_irq is going to require some work. There are a
few users in the tree (I can see three in drivers/pci/host and one in

Hopefully, we can get the maintainers to convert them.


Jazz is not dead. It just smells funny...

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