On Sun, Jul 16, 2023 at 3:12 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > On Fri, Jul 14, 2023 at 01:35:55PM -0700, Vinicius Costa Gomes wrote: > > Bjorn Helgaas <helgaas@xxxxxxxxxx> writes: > > > On Fri, Jul 14, 2023 at 01:05:41PM +0800, Kai-Heng Feng wrote: > > >> When a system that connects to a Thunderbolt dock equipped with I225, > > >> like HP Thunderbolt Dock G4, I225 stops working after S3 resume: > > >> ... > > > > > >> The issue is that the PTM requests are sending before driver resumes the > > >> device. Since the issue can also be observed on Windows, it's quite > > >> likely a firmware/hardware limitation. > > > > > > Does this mean we didn't disable PTM correctly on suspend? Or is the > > > device defective and sending PTM requests even though PTM is disabled? > > > > The way I understand the hardware bug, the device is defective, as you > > said, the device sends PTM messages when "busmastering" is disabled. > > Bus Master Enable controls the ability of a Function to issue Memory > and I/O Read/Write Requests (PCIe r6.0, sec 7.5.1.1.3). PTM uses > Messages, and I don't think they should be affected by Bus Master > Enable. > > I also don't understand the I225 connection. We have these > Uncorrected Non-Fatal errors: > > > >> [ 606.527931] pcieport 0000:00:1d.0: AER: Multiple Uncorrected (Non-Fatal) error received: 0000:00:1d.0 > > >> [ 606.528064] pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID) > > >> [ 606.528068] pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000 > > >> [ 606.528072] pcieport 0000:00:1d.0: [20] UnsupReq (First) > > >> [ 606.528075] pcieport 0000:00:1d.0: AER: TLP Header: 34000000 0a000052 00000000 00000000 > > >> [ 606.528079] pcieport 0000:00:1d.0: AER: Error of this Agent is reported first > > >> [ 606.528098] pcieport 0000:04:01.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID) > > >> [ 606.528101] pcieport 0000:04:01.0: device [8086:1136] error status/mask=00300000/00000000 > > >> [ 606.528105] pcieport 0000:04:01.0: [20] UnsupReq (First) > > >> [ 606.528107] pcieport 0000:04:01.0: [21] ACSViol > > >> [ 606.528110] pcieport 0000:04:01.0: AER: TLP Header: 34000000 04000052 00000000 00000000 > > They are clearly Unsupported Request errors caused by PTM Requests > (decoding at https://bugzilla.kernel.org/show_bug.cgi?id=216850#c9), > but they were logged by 00:1d.0 and 04:01.0. > > The hierarchy is this: > > 00:1d.0 Root Port to [bus 03-6c] > 03:00.0 Switch Upstream Port to [bus 04-6c] > 04:01.0 Switch Downstream Port to [bus 06-38] > 06:00.0 Switch Upstream Port to [bus 07-38] > 07:04.0 Switch Downstream Port to [bus 38] > 38:00.0 igc I225 NIC > > If I225 sent a PTM request when it shouldn't have, i.e., when 07:04.0 > didn't have PTM enabled, the error would have been logged by 07:04.0. > > The fact that the errors were logged by 00:1d.0 and 04:01.0 means that > they were caused by PTM requests from 03:00.0 and 06:00.0. OK, so the PTM is actually fired by the Thunderbolt switch. That means the I225 reset is collateral damage. Let me see if I can reproduce the UR PTM with other devices. Kai-Heng > > Bjorn
