R740 stuck on initializing PCIe in BIOS with PMC adapter and card installed

Hi @michael.pitulej,

As much as I would like to help, but PMC adapter is not tested by engineering, hence we won't be able to understand how to configure nor troubleshoot the server with the PCIe adapter. 

To my personal opinion, since you have moved the same card to a different R740 and it did not work, this would be the server is not compatible with the new card. OR, have you spoken with the vendor about the PMC adapter is compatible with the new card that you are referring to?

the solution worked before, but the vendor added a pci-pcie bridge on one card, and there is another pci-pcie bridge on the PMC adapter card, where previously only the PMC adapter had the bridge.  would this be an issue with stacked bridges?

So after further digging, there is a pericom bridge on one of the cards, the bridge in reverse mode does not reset the retrain bit which will cause devices below this bridge to stop working, which includes the PMC adapter card with its bridge.  there is a fix for the linux kernel i could apply, but i cant get passed the bios so that patch wouldnt do anything until the linux kernel boot.  any suggestions?

Hi,

which linux did you use?

Regards Martin

I am running RHEL7, but the issue is at the Dell BIOS, before the OS boots.  i tried disabling the driver for the slot i am plugging into but it still hangs forever.  there is a known issue for the pericom bridge that i can apply a patch in the kernel supposedly, but i dont even get to the point where i can access the BIOS settings, let alone loading the kernel.  can I possibly disable a slot during boot and enable it at runtime after the OS boots?

I know this is an old post, Was there ever a resolution for this issue?

Kdiff3,

The issue is that the R740 doesn't support the use of PMCs (PCI Mezzanine Cards). So with that we couldn't help as it isn't a tested configuration. You may want to wait to hear from the community on this.