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Commit 977f857c authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk Committed by Bjorn Helgaas
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PCI: move mutex locking out of pci_dev_reset function 



The intent of git commit 6fbf9e7a
"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: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 66f75a5d

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);