Messages in this thread |  | | Date | Sun, 20 Mar 2022 20:52:35 -0700 | Subject | Re: [PATCH v2 1/2] PCI/AER: Disable AER service when link is in L2/L3 ready, L2 and L3 state | From | Sathyanarayanan Kuppuswamy <> |
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On 3/20/22 7:38 PM, Kai-Heng Feng wrote: > On Sun, Mar 20, 2022 at 4:38 AM Sathyanarayanan Kuppuswamy > <sathyanarayanan.kuppuswamy@linux.intel.com> wrote: >> >> >> >> On 1/26/22 6:54 PM, Kai-Heng Feng wrote: >>> Commit 50310600ebda ("iommu/vt-d: Enable PCI ACS for platform opt in >>> hint") enables ACS, and some platforms lose its NVMe after resume from >> >> Why enabling ACS makes platform lose NVMe? Can you add more details >> about the problem? > > I don't have a hardware analyzer, so the only detail I can provide is > the symptom. > I believe the affected system was sent Intel, and there wasn't any > feedback since then.
Since your commit log refers to ACS, I think first we need to understand following points.
1. Why we get ACSViol during S3 resume. Is this just a noise? 2. Why AER recovery fails? 3. Is this common for all platforms, or only happens in your test platform?
If you are not clear about above points, I think you can submit this patch as adding suspend/resume support to AER/DPC driver and not include the issue about ACS.
From your commit log, the problem is not very clear.
> >> >>> S3: >>> [ 50.947816] pcieport 0000:00:1b.0: DPC: containment event, status:0x1f01 source:0x0000 >>> [ 50.947817] pcieport 0000:00:1b.0: DPC: unmasked uncorrectable error detected >>> [ 50.947829] pcieport 0000:00:1b.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Receiver ID) >>> [ 50.947830] pcieport 0000:00:1b.0: device [8086:06ac] error status/mask=00200000/00010000 >>> [ 50.947831] pcieport 0000:00:1b.0: [21] ACSViol (First) >>> [ 50.947841] pcieport 0000:00:1b.0: AER: broadcast error_detected message >>> [ 50.947843] nvme nvme0: frozen state error detected, reset controller >>> >>> It happens right after ACS gets enabled during resume. >>> >>> There's another case, when Thunderbolt reaches D3cold: >>> [ 30.100211] pcieport 0000:00:1d.0: AER: Uncorrected (Non-Fatal) error received: 0000:00:1d.0 >>> [ 30.100251] pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID) >>> [ 30.100256] pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000 >>> [ 30.100262] pcieport 0000:00:1d.0: [20] UnsupReq (First) >>> [ 30.100267] pcieport 0000:00:1d.0: AER: TLP Header: 34000000 08000052 00000000 00000000 >>> [ 30.100372] thunderbolt 0000:0a:00.0: AER: can't recover (no error_detected callback) >> >> no callback message means one or more devices in the given port does not >> support error handler. How is this related to ACS? > > This case is about D3cold, not related to ACS. > And no error_detected is just part of the message. The whole AER > message is more important. > > Kai-Heng > >> >>> [ 30.100401] xhci_hcd 0000:3e:00.0: AER: can't recover (no error_detected callback) >>> [ 30.100427] pcieport 0000:00:1d.0: AER: device recovery failed >>> >>> So disable AER service to avoid the noises from turning power rails >>> on/off when the device is in low power states (D3hot and D3cold), as >>> PCIe spec "5.2 Link State Power Management" states that TLP and DLLP >>> transmission is disabled for a Link in L2/L3 Ready (D3hot), L2 (D3cold >>> with aux power) and L3 (D3cold). >>> >>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209149 >>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215453 >>> Fixes: 50310600ebda ("iommu/vt-d: Enable PCI ACS for platform opt in hint") >>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> >>> --- >>> v2: >>> - Wording change. >>> >>> drivers/pci/pcie/aer.c | 31 +++++++++++++++++++++++++------ >>> 1 file changed, 25 insertions(+), 6 deletions(-) >>> >>> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c >>> index 9fa1f97e5b270..e4e9d4a3098d7 100644 >>> --- a/drivers/pci/pcie/aer.c >>> +++ b/drivers/pci/pcie/aer.c >>> @@ -1367,6 +1367,22 @@ static int aer_probe(struct pcie_device *dev) >>> return 0; >>> } >>> >>> +static int aer_suspend(struct pcie_device *dev) >>> +{ >>> + struct aer_rpc *rpc = get_service_data(dev); >>> + >>> + aer_disable_rootport(rpc); >>> + return 0; >>> +} >>> + >>> +static int aer_resume(struct pcie_device *dev) >>> +{ >>> + struct aer_rpc *rpc = get_service_data(dev); >>> + >>> + aer_enable_rootport(rpc); >>> + return 0; >>> +} >>> + >>> /** >>> * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP >>> * @dev: pointer to Root Port, RCEC, or RCiEP >>> @@ -1433,12 +1449,15 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) >>> } >>> >>> static struct pcie_port_service_driver aerdriver = { >>> - .name = "aer", >>> - .port_type = PCIE_ANY_PORT, >>> - .service = PCIE_PORT_SERVICE_AER, >>> - >>> - .probe = aer_probe, >>> - .remove = aer_remove, >>> + .name = "aer", >>> + .port_type = PCIE_ANY_PORT, >>> + .service = PCIE_PORT_SERVICE_AER, >>> + .probe = aer_probe, >>> + .suspend = aer_suspend, >>> + .resume = aer_resume, >>> + .runtime_suspend = aer_suspend, >>> + .runtime_resume = aer_resume, >>> + .remove = aer_remove, >>> }; >>> >>> /** >> >> -- >> Sathyanarayanan Kuppuswamy >> Linux Kernel Developer
-- Sathyanarayanan Kuppuswamy Linux Kernel Developer
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