On 16 Oct 2020, at 10:22, Bjorn Helgaas wrote:
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.
Agree, this is the patch that the check is needed as we are opening
things up for walking RC_ECs and RC_ENDs as below.
Sean
}
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
