IB/hfi1,PCI: Allow bus reset while probing

Calling into the new API to reset the secondary bus results in a deadlock.
This occurs because the device/bus is already locked at probe time.
Reverting back to the old behavior while the API is improved.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=200985
Fixes: c6a44ba950d1 ("PCI: Rename pci_try_reset_bus() to pci_reset_bus()")
Fixes: 409888e0966e ("IB/hfi1: Use pci_try_reset_bus() for initiating PCI Secondary Bus Reset")
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Cc: Sinan Kaya <okaya@codeaurora.org>

3 files changed, 8 insertions, 7 deletions

diff --git a/drivers/infiniband/hw/hfi1/pcie.c b/drivers/infiniband/hw/hfi1/pcie.c
index eec83757d55f..6c967dde58e7 100644
--- a/drivers/infiniband/hw/hfi1/pcie.c
+++ b/drivers/infiniband/hw/hfi1/pcie.c
@@ -893,14 +893,11 @@ static int trigger_sbr(struct hfi1_devdata *dd)
                 }
 
         /*
-         * A secondary bus reset (SBR) issues a hot reset to our device.
-         * The following routine does a 1s wait after the reset is dropped
-         * per PCI Trhfa (recovery time).  PCIe 3.0 section 6.6.1 -
-         * Conventional Reset, paragraph 3, line 35 also says that a 1s
-         * delay after a reset is required.  Per spec requirements,
-         * the link is either working or not after that point.
+         * This is an end around to do an SBR during probe time. A new API needs
+         * to be implemented to have cleaner interface but this fixes the
+         * current brokenness
          */
-        return pci_reset_bus(dev);
+        return pci_bridge_secondary_bus_reset(dev->bus->self);
 }
 
 /*
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 30b260332a10..1835f3a7aa8d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4547,6 +4547,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
 
         return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
 }
+EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
 
 static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e72ca8dd6241..6925828f9f25 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1235,6 +1235,9 @@ void pci_bus_remove_resources(struct pci_bus *bus);
 int devm_request_pci_bus_resources(struct device *dev,
                                    struct list_head *resources);
 
+/* Temporary until new and working PCI SBR API in place */
+int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
+
 #define pci_bus_for_each_resource(bus, res, i)                          \
         for (i = 0;                                                     \
             (res = pci_bus_resource_n(bus, i)) || i < PCI_BRIDGE_RESOURCE_NUM; \