Commit bfc45606 authored by Dennis Dalessandro's avatar Dennis Dalessandro Committed by Bjorn Helgaas
Browse files

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: c6a44ba9 ("PCI: Rename pci_try_reset_bus() to pci_reset_bus()")
Fixes: 409888e0 ("IB/hfi1: Use pci_try_reset_bus() for initiating PCI Secondary Bus Reset")
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarMichael J. Ruhl <michael.j.ruhl@intel.com>
Cc: Sinan Kaya <okaya@codeaurora.org>
parent d8a52810

drivers/infiniband/hw/hfi1/pcie.c

+4 −7
Original line number Diff line number Diff line
@@ -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);

}



/*

drivers/pci/pci.c

+1 −0
Original line number Diff line number Diff line
@@ -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)

{

include/linux/pci.h

+3 −0
Original line number Diff line number Diff line
@@ -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; \

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