PCIDevice->Open method failing with kIOReturnNotOpen

Question

Created Sep ’20

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Hi,
I am able to activate the PCI DEXT and matching is also happening. When I connect/Disconnect then Driver is loading and unloading.

After this I followed below wwdc2020 link:
https://developer.apple.com/videos/play/wwdc2020/10210/

The very first API used in this presentation is failing.

PCIDevice->Open method is failing with error: kIOReturnNotOpen (0x2cd)

This I have tried to call before and after RegisterService method call. In both case this Open method call is failing.
Even I tried Open method calling from Externalmethod i.e.

App->UserClient->ExternalMethod->MainDriverOpenSessionToPCIDevice

In all case, Open is failing.

Anyone faced this error??
If someone is able to Open session to PIC Device then it please let me know what steps to follow.
Thanks

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Answer 1

anshu1102 OP

Sep ’20

Hi,
I'm also observing this issue. For me also IOPCIDevice->Open is failing but ConfugurationReadXX/ConfigurationWriteXX is not throwing any error and I can access PCI register to fetch
Vendor ID: kIOPCIConfigurationOffsetVendorID and
Device ID: kIOPCIConfigurationOffsetDeviceID

So I can confirm that My DEXT is matching with my PCI device.

In WWDC2020 presentation: https://developer.apple.com/videos/play/wwdc2020/10210/ just IOPCIDevice->Open is required to communicate with device but this itself is failing.
I'm stuck here..

Any help would be appreciated..
Thanks

0

Answer 2

abishekmadhu OP

May ’21

I am also facing this exact issue where Open(this, 0) call fails in Start() but accessing the configuration space using ConfigurationReadXX/ConfigurationWriteXX works fine. In case of accessing the memory space, MemoryReadXX is successful but MemoryWriteXX crashes whenever I try to access any offset in memory index 0.

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