On Thu, Jan 13, 2022 at 08:13:55AM +0100, Stefan Roese wrote: > On 1/12/22 18:49, Bjorn Helgaas wrote: > > Ah. I assume you have: > > > > 00:00.0 Root Port to [bus 01-??] > > 01:00.0 Switch Upstream Port to [bus 02-??] > > 02:0?.0 Switch Downstream Port to [bus 04-??] > > This is correct, yes. > > > pcie_portdrv_probe() claims 00:00.0 and clears CERE NFERE FERE URRE. > > > > aer_probe() claims 00:00.0 and enables CERE NFERE FERE URRE for all > > downstream devices, including 01:00.0. > > > > pcie_portdrv_probe() claims 01:00.0 and clears CERE NFERE FERE URRE > > again. > > > > aer_probe() declines to claim 01:00.0 because it's not a Root Port, so > > CERE NFERE FERE URRE remain cleared. > I'm baffled a bit, that this problem of AER reporting being disabled in > the DevCtl regs of PCIe ports (all non root ports) was not noticed for > this long time. As AER is practically disabled in such setups. The more common configuration is a Root Port leading directly to an Endpoint. In that case, there would be no pcie_portdrv_probe() in the middle to disable reporting after aer_probe() has enabled it. The issue you're seeing happens because of the switch in the middle, which is becoming more common recently with Thunderbolt. I poked around on my laptop (Dell 5520 running v5.4): 00:01.0 Root Port to [bus 01] CorrErr- 01:00.0 NVIDIA GPU CorrErr- 00:1c.0 Root Port to [bus 02] AER CorrErr+ 02:00.0 Intel NIC AER CorrErr- <-- iwlwifi 00:1c.1 Root Port to [bus 03] AER CorrErr+ 03:00.0 Realtek card reader AER CorrErr- <-- rtsx_pci 00:1d.0 Root Port to [bus 04] AER CorrErr+ 04:00.0 NVMe AER CorrErr+ 00:1d.6 Root Port to [bus 06-3e] AER CorrErr+ 06:00.0 Thunderbolt USP to [bus 07-3e] AER CorrErr- 07:00.0 Thunderbolt DSP to [bus 08] AER CorrErr- ... CorrErr- Everything in the Thunderbolt hierarchy has reporting disabled, probably because of the issue you are pointing out. I can't explain the iwlwifi and rtsx_pci cases. Both devices have AER and are directly below a Root Port that also has AER, so I would think reporting should be enabled. Bjorn
