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Commit f85876ba authored by Yu Zhao's avatar Yu Zhao Committed by Jesse Barnes
Browse files

PCI: support PM D0hot->D3 transition reset 



PCI PM 1.2 specifies that the device will perform an internal reset upon
transitioning from D3hot to D0 when the NO_SOFT_RESET bit is clear. This
method can be used to reset a function if neither PCIe FLR nor PCI AF FLR
are supported.

Reviewed-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarYu Zhao <yu.zhao@intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 8c1c699f

drivers/pci/pci.c

+34 −0
Original line number Original line Diff line number Diff line
@@ -2132,6 +2132,36 @@ static int pci_af_flr(struct pci_dev *dev, int probe) 
	return 0;

	return 0;

}

}





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

{

	u16 csr;



	if (!dev->pm_cap)

		return -ENOTTY;



	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);

	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)

		return -ENOTTY;



	if (probe)

		return 0;



	if (dev->current_state != PCI_D0)

		return -EINVAL;



	csr &= ~PCI_PM_CTRL_STATE_MASK;

	csr |= PCI_D3hot;

	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);

	msleep(pci_pm_d3_delay);



	csr &= ~PCI_PM_CTRL_STATE_MASK;

	csr |= PCI_D0;

	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);

	msleep(pci_pm_d3_delay);



	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;

	int rc;
@@ -2149,6 +2179,10 @@ static int pci_dev_reset(struct pci_dev *dev, int probe) 
		goto done;

		goto done;





	rc = pci_af_flr(dev, probe);

	rc = pci_af_flr(dev, probe);

	if (rc != -ENOTTY)

		goto done;



	rc = pci_pm_reset(dev, probe);

done:

done:

	if (!probe) {

	if (!probe) {

		up(&dev->dev.sem);

		up(&dev->dev.sem);