On Thu, Oct 15, 2020 at 05:11:08PM -0700, Sean V Kelley wrote: > From: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > > In some cases a bridge may not exist as the hardware controlling may be > handled only by firmware and so is not visible to the OS. This scenario is > also possible in future use cases involving non-native use of RCECs by > firmware. > > Explicitly apply conditional logic around these resets by limiting them to > Root Ports and Downstream Ports. > > Link: https://lore.kernel.org/r/20201002184735.1229220-8-seanvk.dev@xxxxxxxxxxxxxxxx > Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > --- > drivers/pci/pcie/err.c | 31 +++++++++++++++++++++++++------ > 1 file changed, 25 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c > index 8b53aecdb43d..7883c9791562 100644 > --- a/drivers/pci/pcie/err.c > +++ b/drivers/pci/pcie/err.c > @@ -148,13 +148,17 @@ static int report_resume(struct pci_dev *dev, void *data) > > /** > * pci_walk_bridge - walk bridges potentially AER affected > - * @bridge: bridge which may be a Port > + * @bridge: bridge which may be a Port, an RCEC with associated RCiEPs, > + * or an RCiEP associated with an RCEC > * @cb: callback to be called for each device found > * @userdata: arbitrary pointer to be passed to callback > * > * If the device provided is a bridge, walk the subordinate bus, including > * any bridged devices on buses under this bus. Call the provided callback > * on each device found. > + * > + * If the device provided has no subordinate bus, call the callback on the > + * device itself. > */ > static void pci_walk_bridge(struct pci_dev *bridge, > int (*cb)(struct pci_dev *, void *), > @@ -162,6 +166,8 @@ static void pci_walk_bridge(struct pci_dev *bridge, > { > if (bridge->subordinate) > pci_walk_bus(bridge->subordinate, cb, userdata); > + else > + cb(bridge, userdata); Looks like *this* is the patch where the "no subordinate bus" case becomes possible? If you agree, I can just move the test here, no need to repost. > } > > pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > @@ -174,10 +180,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > > /* > * Error recovery runs on all subordinates of the bridge. If the > - * bridge detected the error, it is cleared at the end. > + * bridge detected the error, it is cleared at the end. For RCiEPs > + * we should reset just the RCiEP itself. > */ > if (type == PCI_EXP_TYPE_ROOT_PORT || > - type == PCI_EXP_TYPE_DOWNSTREAM) > + type == PCI_EXP_TYPE_DOWNSTREAM || > + type == PCI_EXP_TYPE_RC_EC || > + type == PCI_EXP_TYPE_RC_END) > bridge = dev; > else > bridge = pci_upstream_bridge(dev); > @@ -185,6 +194,12 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > pci_dbg(bridge, "broadcast error_detected message\n"); > if (state == pci_channel_io_frozen) { > pci_walk_bridge(bridge, report_frozen_detected, &status); > + if (type == PCI_EXP_TYPE_RC_END) { > + pci_warn(dev, "subordinate device reset not possible for RCiEP\n"); > + status = PCI_ERS_RESULT_NONE; > + goto failed; > + } > + > status = reset_subordinates(bridge); > if (status != PCI_ERS_RESULT_RECOVERED) { > pci_warn(bridge, "subordinate device reset failed\n"); > @@ -217,9 +232,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > pci_dbg(bridge, "broadcast resume message\n"); > pci_walk_bridge(bridge, report_resume, &status); > > - if (pcie_aer_is_native(bridge)) > - pcie_clear_device_status(bridge); > - pci_aer_clear_nonfatal_status(bridge); > + if (type == PCI_EXP_TYPE_ROOT_PORT || > + type == PCI_EXP_TYPE_DOWNSTREAM || > + type == PCI_EXP_TYPE_RC_EC) { > + if (pcie_aer_is_native(bridge)) > + pcie_clear_device_status(bridge); > + pci_aer_clear_nonfatal_status(bridge); > + } > pci_info(bridge, "device recovery successful\n"); > return status; > > -- > 2.28.0 >
