Re: [PATCH] Add option to passively listen for PCIE hotplug events

From: Kenji Kaneshige
Date: Mon Nov 03 2008 - 22:13:05 EST


Matthew Garrett wrote:
On Tue, Nov 04, 2008 at 11:29:43AM +0900, Kenji Kaneshige wrote:
Matthew Garrett wrote:
What do you mean by "not work properly"? The hardware we've tested with fires events even without an OSHP method being present. That's the case we're trying to deal with.

Because the explanation of PCI Express Native Hot Plug control bit in
_OSC return value in PCI firmware spec says

"... If firmware allows the operating system control of this feature,
then in the context of the _OSC method, it must ensure that all hot
plug events are routed to device interrupts as described in the PCI
Express Base Specification. ..."

My understanding is that it is not ensured that all hot plug events
are routed to device interrupts, if hotplug control is not granted.

My understanding is that in the worst case the hardware/firmware won't give us any events - that's basically equivalent to not having the driver loaded at all. On hardware that gives us the events anyway, we get some extra functionality.

Thanks for the feedback!

Ok, I understood that my worries are already within the scope of the
assumption.

Thanks,
Kenji Kaneshige





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