On 2/1/2019 4:52 PM, Bjorn Helgaas wrote:
See https://bugzilla.kernel.org/show_bug.cgi?id=202425. Robert bisected a problem with a 3ware 9650SE-2LP controller to 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported") and verified that reverting it solves the problem. We have found issues in the past where Root Ports don't handle extended tags correctly and have added quirks to avoid use of them: 1b30dfd376e2 ("PCI: Mark Broadcom HT1100 and HT2000 Root Port Extended Tags as broken") 62ce94a7a5a5 ("PCI: Mark Broadcom HT2100 Root Port Extended Tags as broken") I don't know yet what Root Ports Robert has, but maybe we need a similar quirk? I'm pretty sure Root Ports that don't handle extended tags are out of spec, so it would be ideal if we could get the manufacturer to provide an erratum as documentation.
I agree. The issue needs to be directed to AMD. PCI spec says it is safe to enable this option. I also have not heart of a single complaint from Intel systems.
Bjorn
