Messages in this thread |  | | Date | Fri, 10 Jul 2020 10:18:00 +0100 | From | Lorenzo Pieralisi <> | Subject | Re: [PATCH v3] PCI: aardvark: Don't touch PCIe registers if no card connected |
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On Thu, Jul 09, 2020 at 05:09:59PM +0200, Pali Rohár wrote:
[...]
> > I understand that but the bridge bus resource can be trimmed to just > > contain the root bus because that's the only one where there is a > > chance you can enumerate a device. > > It is possible to register only root bridge without endpoint?
It is possible to register the root bridge with a trimmed IORESOURCE_BUS so that you don't enumerate anything other than the root port.
> > I would like to get Bjorn's opinion on this, I don't like these "link is > > up" checks in config accessors (they are racy and honestly it is a > > run-time check that does not make much sense, either it is always > > true/false or it is inevitably racy) > > It is runtime check, but does not have to be always true/false. I have > tested more Compex wifi cards and under certain conditions they > "disappear" from the bus during usage.
I would be very grateful if you could describe what happens in HW when these conditions trigger - I would like to understand if this issue is aardvark specific or it isn't.
> So I think it still make sense to do this "fast" check as it is only > optimization.
I will merge this patch but I'd also like to understand the underlying issue better.
Thanks, Lorenzo
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