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PCI: move mutex locking out of pci_dev_reset function

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The intent of git commit 6fbf9e7a90
"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>
This commit is contained in:
Konrad Rzeszutek Wilk 2012-04-24 13:15:18 -06:00 committed by Bjorn Helgaas
parent 66f75a5d02
commit 977f857ca5
1 changed files with 17 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/pci/pci.c
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@ -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);