MSI interrupts on PCIE root ports is not enabled making hot plug impossible

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Environment

SUSE Linux Enterprise Server 10 Support Pack 2

Situation

Hotplug is prevented due to the MSI interrupts on PCIE root ports being disabled.
This means that Hotplug capable PCI devices will not be able replaceable under Hotplug conditions.

Resolution

The workaround is to enable hotplug using pciehp in the absence of MSI on pcie root ports. The pciehp driver has a parameter pciehp_poll_mode=1. When the pciehp driver is loaded with this parameter the hotplug actions work. Also no stacktrace is thrown and no IRQs are disabled.

To load the pciehp driver with the following command:

modprobe pciehp pciehp_poll_mode=1

Or edit /etc/modprobe.conf.local and add the line:

options pciehp pciehp_poll_mode=1

Disclaimer

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