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Commit 1ca88797 authored by Sheng Yang's avatar Sheng Yang Committed by Jesse Barnes
Browse files

PCI: Extend pci_reset_function() to support PCI Advanced Features 



Some PCI devices implement PCI Advanced Features, which means they
support Function Level Reset(FLR).  Implement support for that in
pci_reset_function.

Signed-off-by: default avatarSheng Yang <sheng@linux.intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent f7b7baae

drivers/pci/pci.c

+41 −0
Original line number Original line Diff line number Diff line
@@ -1789,6 +1789,43 @@ static int __pcie_flr(struct pci_dev *dev, int probe) 
	return 0;

	return 0;

}

}





static int __pci_af_flr(struct pci_dev *dev, int probe)

{

	int cappos = pci_find_capability(dev, PCI_CAP_ID_AF);

	u8 status;

	u8 cap;



	if (!cappos)

		return -ENOTTY;

	pci_read_config_byte(dev, cappos + PCI_AF_CAP, &cap);

	if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))

		return -ENOTTY;



	if (probe)

		return 0;



	pci_block_user_cfg_access(dev);



	/* Wait for Transaction Pending bit clean */

	msleep(100);

	pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status);

	if (status & PCI_AF_STATUS_TP) {

		dev_info(&dev->dev, "Busy after 100ms while trying to"

				" reset; sleeping for 1 second\n");

		ssleep(1);

		pci_read_config_byte(dev,

				cappos + PCI_AF_STATUS, &status);

		if (status & PCI_AF_STATUS_TP)

			dev_info(&dev->dev, "Still busy after 1s; "

					"proceeding with reset anyway\n");

	}

	pci_write_config_byte(dev, cappos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);

	mdelay(100);



	pci_unblock_user_cfg_access(dev);

	return 0;

}



static int __pci_reset_function(struct pci_dev *pdev, int probe)

static int __pci_reset_function(struct pci_dev *pdev, int probe)

{

{

	int res;

	int res;
@@ -1797,6 +1834,10 @@ static int __pci_reset_function(struct pci_dev *pdev, int probe) 
	if (res != -ENOTTY)

	if (res != -ENOTTY)

		return res;

		return res;





	res = __pci_af_flr(pdev, probe);

	if (res != -ENOTTY)

		return res;



	return res;

	return res;

}

}