* when will irq parameter in struct pci_dev be used
@ 2015-12-01 5:30 bharat kumar gogada
2015-12-01 9:48 ` Arnd Bergmann
0 siblings, 1 reply; 3+ messages in thread
From: bharat kumar gogada @ 2015-12-01 5:30 UTC (permalink / raw)
To: linux-arm-kernel
Hi, In arm64 when will the 'irq' parameter in struct pci_dev will be used in
kernel, how it will be used in legacy interrupts and how it will be used in
MSI interrupts, when we have MSI domains.
Bharat
^ permalink raw reply [flat|nested] 3+ messages in thread
* when will irq parameter in struct pci_dev be used
2015-12-01 5:30 when will irq parameter in struct pci_dev be used bharat kumar gogada
@ 2015-12-01 9:48 ` Arnd Bergmann
2015-12-01 10:03 ` Bharat Kumar Gogada
0 siblings, 1 reply; 3+ messages in thread
From: Arnd Bergmann @ 2015-12-01 9:48 UTC (permalink / raw)
To: linux-arm-kernel
On Tuesday 01 December 2015 05:30:45 bharat kumar gogada wrote:
> Hi, In arm64 when will the 'irq' parameter in struct pci_dev will be used in
> kernel, how it will be used in legacy interrupts and how it will be used in
> MSI interrupts, when we have MSI domains.
The number is initialized with whatever legacy interrupt you list in
the interrupt-map property of the PCI host device node for this device,
and drivers are supposed to use it from there.
For MSI, see Documentation/PCI/MSI-HOWTO.txt
Arnd
^ permalink raw reply [flat|nested] 3+ messages in thread
* when will irq parameter in struct pci_dev be used
2015-12-01 9:48 ` Arnd Bergmann
@ 2015-12-01 10:03 ` Bharat Kumar Gogada
0 siblings, 0 replies; 3+ messages in thread
From: Bharat Kumar Gogada @ 2015-12-01 10:03 UTC (permalink / raw)
To: linux-arm-kernel
> Subject: Re: when will irq parameter in struct pci_dev be used
>
> On Tuesday 01 December 2015 05:30:45 bharat kumar gogada wrote:
> > Hi, In arm64 when will the 'irq' parameter in struct pci_dev will be
> > used in kernel, how it will be used in legacy interrupts and how it
> > will be used in MSI interrupts, when we have MSI domains.
>
> The number is initialized with whatever legacy interrupt you list in the
> interrupt-map property of the PCI host device node for this device, and
> drivers are supposed to use it from there.
>
> For MSI, see Documentation/PCI/MSI-HOWTO.txt
>
Yes I have seen that in arm/arch64/kernel/pci.c, in function pcibios_add_device this number is getting updated w.r.t to interrupt map property. So the host bridge gets this number, so you meant like, first end point device will get this irq number when it asks through request irq, if it is legacy interrupt, and if another legacy request comes this will be incremental. If it is MSI it depends on MSI domain present in root port driver, End point will get different number irrespective of this irq number.
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2015-12-01 5:30 when will irq parameter in struct pci_dev be used bharat kumar gogada
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