Messages in this thread | | | Date | Wed, 2 Apr 2014 13:23:33 -0400 | From | Murali Karicheri <> | Subject | Re: [RESEND: RFC PATCH 3/3] pcie: keystone: add pcie driver based on designware core driver |
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On 4/2/2014 12:47 PM, Andrew Murray wrote: > On 2 April 2014 16:43, Murali Karicheri <m-karicheri2@ti.com> wrote: > >> Keystone pcie driver is developed based on other dw based pcie drivers >> >> such as pci-exynos that uses subsys_initcall(). I am new to this list, >> >> probably Jingoo (copied) has some history on why we can't use module. >> For now I will keep it as is and can be re-visited in the next revisions. >> Also I will experiment with PCIE port driver as well. >> >> >> BTW, PCIE driver currently uses Legacy or MSI IRQ. Keystone PCI has >> a platform IRQ. Is DT based irq configuration is the appropriate way >> to add this capability? > As far as I am aware - the PCI standards define a particular way for > devices to describe which interrupt will be used for things like > hotplug, AER and PME. These interrupts are always PCI interrupts (i.e. > MSI/MSI-X/legacy). Thus the port services code in the kernel uses > standard configuration space accesses to determine the interrupt to > use. Also note that it's not just the host bridge that can provide > these services but any PCIE device, I guess in this sense a host > bridge is treated like any other device. > > If my understanding is correct I don't believe the current port > services code allows exceptions to this, i.e. to say this host bridge > actually uses a platform IRQ for AER rather than an MSI. Though this > may be quite useful as I suspect many host bridges provide interrupts > for things like PME through platform IRQs rather that PCI interrupts. > > Does the Keystone have platform IRQs for things like AER? Is that > because the IP makes these events available through platform IRQs in > addition to the standard PCI means? > > Andrew Murray Andrew,
Yes. Keystone PCIe hw is based on designware hw version v3.65 that implements Error interrupt as a platform IRQ only (not in addition) and unfortunately standard PCI means are not supported. The latter versions do support standard PCI means.
Murali
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