PCI: move mutex locking out of pci_dev_reset function (977f857c) · Commits · 戴 / test

The intent of git commit "PCI: Introduce __pci_reset_function_locked to be used when holding device_lock." was to have a non-locking function that would call pci_dev_reset function. But it fell short of that by just probing and not actually reseting the device. To make that work we need a way to move the lock around device_lock to not be in pci_dev_reset (as the caller of __pci_reset_function_locked already holds said lock). We do this by renaming pci_dev_reset to __pci_dev_reset and bubbling said mutex out of __pci_dev_reset to pci_dev_reset (a wrapper around __pci_dev_reset). The __pci_reset_function_locked can now call __pci_dev_reset without having to worry about the dead-lock. Signed-off-by:

Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:

Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci.c

+17 −10

Original line number	Diff line number	Diff line
		@@ -3164,18 +3164,12 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
		return 0;
		}

		static int pci_dev_reset(struct pci_dev *dev, int probe)
		static int __pci_dev_reset(struct pci_dev *dev, int probe)
		{
		int rc;

		might_sleep();

		if (!probe) {
		pci_cfg_access_lock(dev);
		/* block PM suspend, driver probe, etc. */
		device_lock(&dev->dev);
		}

		rc = pci_dev_specific_reset(dev, probe);
		if (rc != -ENOTTY)
		goto done;
		@@ -3194,14 +3188,27 @@ static int pci_dev_reset(struct pci_dev *dev, int probe)

		rc = pci_parent_bus_reset(dev, probe);
		done:
		return rc;
		}

		static int pci_dev_reset(struct pci_dev *dev, int probe)
		{
		int rc;

		if (!probe) {
		pci_cfg_access_lock(dev);
		/* block PM suspend, driver probe, etc. */
		device_lock(&dev->dev);
		}

		rc = __pci_dev_reset(dev, probe);

		if (!probe) {
		device_unlock(&dev->dev);
		pci_cfg_access_unlock(dev);
		}

		return rc;
		}

		/**
		* __pci_reset_function - reset a PCI device function
		* @dev: PCI device to reset
		@@ -3246,7 +3253,7 @@ EXPORT_SYMBOL_GPL(__pci_reset_function);
		*/
		int __pci_reset_function_locked(struct pci_dev *dev)
		{
		return pci_dev_reset(dev, 1);
		return __pci_dev_reset(dev, 0);
		}
		EXPORT_SYMBOL_GPL(__pci_reset_function_locked);

Admin message