Re: [PATCH v4 3/3] PCI/AER: Report fatal errors of RCiEP and EP if link recoverd

[Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>]

在 2025/3/3 11:43, Sathyanarayanan Kuppuswamy 写道:
> On 2/16/25 6:42 PM, Shuai Xue wrote:
> > The AER driver has historically avoided reading the configuration space of
> > an endpoint or RCiEP that reported a fatal error, considering the link to
> > that device unreliable. Consequently, when a fatal error occurs, the AER
> > and DPC drivers do not report specific error types, resulting in logs like:
> >
> >    pcieport 0000:30:03.0: EDR: EDR event received
> >    pcieport 0000:30:03.0: DPC: containment event, status:0x0005 source:0x3400
> >    pcieport 0000:30:03.0: DPC: ERR_FATAL detected
> >    pcieport 0000:30:03.0: AER: broadcast error_detected message
> >    nvme nvme0: frozen state error detected, reset controller
> >    nvme 0000:34:00.0: ready 0ms after DPC
> >    pcieport 0000:30:03.0: AER: broadcast slot_reset message
> >
> > AER status registers are sticky and Write-1-to-clear. If the link recovered
> > after hot reset, we can still safely access AER status of the error device.
> > In such case, report fatal errors which helps to figure out the error root
> > case.
> >
> > After this patch, the logs like:
> >
> >    pcieport 0000:30:03.0: EDR: EDR event received
> >    pcieport 0000:30:03.0: DPC: containment event, status:0x0005 source:0x3400
> >    pcieport 0000:30:03.0: DPC: ERR_FATAL detected
> >    pcieport 0000:30:03.0: AER: broadcast error_detected message
> >    nvme nvme0: frozen state error detected, reset controller
> >    pcieport 0000:30:03.0: waiting 100 ms for downstream link, after activation
> >    nvme 0000:34:00.0: ready 0ms after DPC
> >    nvme 0000:34:00.0: PCIe Bus Error: severity=Uncorrectable (Fatal), type=Data Link Layer, (Receiver ID)
> >    nvme 0000:34:00.0:   device [144d:a804] error status/mask=00000010/00504000
> >    nvme 0000:34:00.0:    [ 4] DLP                    (First)
> >    pcieport 0000:30:03.0: AER: broadcast slot_reset message
>
> IMO, above info about device error details is more of a debug info. Since the
> main use of this info use to understand more details about the recovered
> DPC error. So I think is better to print with debug tag. Lets see what others
> think.
>
> Code wise, looks fine to me.

thanks, looking forward to more feedback.
> > Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/pci/pci.h      |  3 ++-
> >   drivers/pci/pcie/aer.c | 11 +++++++----
> >   drivers/pci/pcie/dpc.c |  2 +-
> >   drivers/pci/pcie/err.c |  9 +++++++++
> >   4 files changed, 19 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> > index 870d2fbd6ff2..e852fa58b250 100644
> > --- a/drivers/pci/pci.h
> > +++ b/drivers/pci/pci.h
> > @@ -549,7 +549,8 @@ struct aer_err_info {
> >       struct pcie_tlp_log tlp;    /* TLP Header */
> >   };
> > -int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
> > +int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info,
> > +                  bool link_healthy);
> >   void aer_print_error(struct pci_dev *dev, struct aer_err_info *info);
> >   int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
> > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> > index 508474e17183..bfb67db074f0 100644
> > --- a/drivers/pci/pcie/aer.c
> > +++ b/drivers/pci/pcie/aer.c
> > @@ -1197,12 +1197,14 @@ EXPORT_SYMBOL_GPL(aer_recover_queue);
> >    * aer_get_device_error_info - read error status from dev and store it to info
> >    * @dev: pointer to the device expected to have a error record
> >    * @info: pointer to structure to store the error record
> > + * @link_healthy: link is healthy or not
> >    *
> >    * Return 1 on success, 0 on error.
> >    *
> >    * Note that @info is reused among all error devices. Clear fields properly.
> >    */
> > -int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
> > +int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info,
> > +                  bool link_healthy)
> >   {
> >       int type = pci_pcie_type(dev);
> >       int aer = dev->aer_cap;
> > @@ -1226,7 +1228,8 @@ int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
> >       } else if (type == PCI_EXP_TYPE_ROOT_PORT ||
> >              type == PCI_EXP_TYPE_RC_EC ||
> >              type == PCI_EXP_TYPE_DOWNSTREAM ||
> > -           info->severity == AER_NONFATAL) {
> > +           info->severity == AER_NONFATAL ||
> > +           (info->severity == AER_FATAL && link_healthy)) {
> >           /* Link is still healthy for IO reads */
> >           pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
> > @@ -1258,11 +1261,11 @@ static inline void aer_process_err_devices(struct aer_err_info *e_info)
> >       /* Report all before handle them, not to lost records by reset etc. */
> >       for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
> > -        if (aer_get_device_error_info(e_info->dev[i], e_info))
> > +        if (aer_get_device_error_info(e_info->dev[i], e_info, false))
> >               aer_print_error(e_info->dev[i], e_info);
> >       }
> >       for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
> > -        if (aer_get_device_error_info(e_info->dev[i], e_info))
> > +        if (aer_get_device_error_info(e_info->dev[i], e_info, false))
> >               handle_error_source(e_info->dev[i], e_info);
> >       }
> >   }
> > diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
> > index ea3ea989afa7..2d3dd831b755 100644
> > --- a/drivers/pci/pcie/dpc.c
> > +++ b/drivers/pci/pcie/dpc.c
> > @@ -303,7 +303,7 @@ struct pci_dev *dpc_process_error(struct pci_dev *pdev)
> >           dpc_process_rp_pio_error(pdev);
> >       else if (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_UNCOR &&
> >            dpc_get_aer_uncorrect_severity(pdev, &info) &&
> > -         aer_get_device_error_info(pdev, &info)) {
> > +         aer_get_device_error_info(pdev, &info, false)) {
> >           aer_print_error(pdev, &info);
> >           pci_aer_clear_nonfatal_status(pdev);
> >           pci_aer_clear_fatal_status(pdev);
> > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> > index 31090770fffc..462577b8d75a 100644
> > --- a/drivers/pci/pcie/err.c
> > +++ b/drivers/pci/pcie/err.c
> > @@ -196,6 +196,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> >       struct pci_dev *bridge;
> >       pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
> >       struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
> > +    struct aer_err_info info;
> >       /*
> >        * If the error was detected by a Root Port, Downstream Port, RCEC,
> > @@ -223,6 +224,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> >               pci_warn(bridge, "subordinate device reset failed\n");
> >               goto failed;
> >           }
> > +
> > +        info.severity = AER_FATAL;
> > +        /* Link recovered, report fatal errors of RCiEP or EP */
> > +        if ((type == PCI_EXP_TYPE_ENDPOINT ||
> > +             type == PCI_EXP_TYPE_RC_END) &&
> > +            aer_get_device_error_info(dev, &info, true))
> > +            aer_print_error(dev, &info);
> >       } else {
> >           pci_walk_bridge(bridge, report_normal_detected, &status);
> >       }
> > @@ -259,6 +267,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> >       if (host->native_aer || pcie_ports_native) {
> >           pcie_clear_device_status(dev);
> >           pci_aer_clear_nonfatal_status(dev);
> > +        pci_aer_clear_fatal_status(dev);
>
> Add some info about above change in the commit log.

Will do.

Thanks.
Shuai