Commit 7957d201 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Bjorn Helgaas
Browse files

PCI/PM: Relocate pci_set_low_power_state() 

Because pci_set_power_state() is the only caller of
pci_set_low_power_state(), put the latter next to the former.

No functional impact.

Link: https://lore.kernel.org/r/3202976.44csPzL39Z@kreacher


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 10aa5377

drivers/pci/pci.c

+79 −79
Original line number Diff line number Diff line
@@ -1067,85 +1067,6 @@ static inline bool platform_pci_bridge_d3(struct pci_dev *dev) 
	return acpi_pci_bridge_d3(dev);

}



/**

 * pci_set_low_power_state - Put a PCI device into a low-power state.

 * @dev: PCI device to handle.

 * @state: PCI power state (D1, D2, D3hot) to put the device into.

 *

 * Use the device's PCI_PM_CTRL register to put it into a low-power state.

 *

 * RETURN VALUE:

 * -EINVAL if the requested state is invalid.

 * -EIO if device does not support PCI PM or its PM capabilities register has a

 * wrong version, or device doesn't support the requested state.

 * 0 if device already is in the requested state.

 * 0 if device's power state has been successfully changed.

 */

static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state)

{

	u16 pmcsr;



	/* Check if we're already there */

	if (dev->current_state == state)

		return 0;



	if (!dev->pm_cap)

		return -EIO;



	if (state < PCI_D1 || state > PCI_D3hot)

		return -EINVAL;



	/*

	 * Validate transition: We can enter D0 from any state, but if

	 * we're already in a low-power state, we can only go deeper.  E.g.,

	 * we can go from D1 to D3, but we can't go directly from D3 to D1;

	 * we'd have to go from D3 to D0, then to D1.

	 */

	if (dev->current_state <= PCI_D3cold && dev->current_state > state) {

		pci_err(dev, "invalid power transition (from %s to %s)\n",

			pci_power_name(dev->current_state),

			pci_power_name(state));

		return -EINVAL;

	}



	/* Check if this device supports the desired state */

	if ((state == PCI_D1 && !dev->d1_support)

	   || (state == PCI_D2 && !dev->d2_support))

		return -EIO;



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

	if (PCI_POSSIBLE_ERROR(pmcsr)) {

		pci_err(dev, "Unable to change power state from %s to %s, device inaccessible\n",

			pci_power_name(dev->current_state),

			pci_power_name(state));

		return -EIO;

	}



	pmcsr &= ~PCI_PM_CTRL_STATE_MASK;

	pmcsr |= state;



	/* Enter specified state */

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



	/* Mandatory power management transition delays; see PCI PM 1.2. */

	if (state == PCI_D3hot)

		pci_dev_d3_sleep(dev);

	else if (state == PCI_D2)

		udelay(PCI_PM_D2_DELAY);



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

	dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;

	if (dev->current_state != state)

		pci_info_ratelimited(dev, "Refused to change power state from %s to %s\n",

				     pci_power_name(dev->current_state),

				     pci_power_name(state));



	if (dev->bus->self)

		pcie_aspm_pm_state_change(dev->bus->self);



	return 0;

}



/**

 * pci_update_current_state - Read power state of given device and cache it

 * @dev: PCI device to handle.
@@ -1363,6 +1284,85 @@ void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state) 
		pci_walk_bus(bus, __pci_dev_set_current_state, &state);

}



/**

 * pci_set_low_power_state - Put a PCI device into a low-power state.

 * @dev: PCI device to handle.

 * @state: PCI power state (D1, D2, D3hot) to put the device into.

 *

 * Use the device's PCI_PM_CTRL register to put it into a low-power state.

 *

 * RETURN VALUE:

 * -EINVAL if the requested state is invalid.

 * -EIO if device does not support PCI PM or its PM capabilities register has a

 * wrong version, or device doesn't support the requested state.

 * 0 if device already is in the requested state.

 * 0 if device's power state has been successfully changed.

 */

static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state)

{

	u16 pmcsr;



	/* Check if we're already there */

	if (dev->current_state == state)

		return 0;



	if (!dev->pm_cap)

		return -EIO;



	if (state < PCI_D1 || state > PCI_D3hot)

		return -EINVAL;



	/*

	 * Validate transition: We can enter D0 from any state, but if

	 * we're already in a low-power state, we can only go deeper.  E.g.,

	 * we can go from D1 to D3, but we can't go directly from D3 to D1;

	 * we'd have to go from D3 to D0, then to D1.

	 */

	if (dev->current_state <= PCI_D3cold && dev->current_state > state) {

		pci_err(dev, "invalid power transition (from %s to %s)\n",

			pci_power_name(dev->current_state),

			pci_power_name(state));

		return -EINVAL;

	}



	/* Check if this device supports the desired state */

	if ((state == PCI_D1 && !dev->d1_support)

	   || (state == PCI_D2 && !dev->d2_support))

		return -EIO;



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

	if (PCI_POSSIBLE_ERROR(pmcsr)) {

		pci_err(dev, "Unable to change power state from %s to %s, device inaccessible\n",

			pci_power_name(dev->current_state),

			pci_power_name(state));

		return -EIO;

	}



	pmcsr &= ~PCI_PM_CTRL_STATE_MASK;

	pmcsr |= state;



	/* Enter specified state */

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



	/* Mandatory power management transition delays; see PCI PM 1.2. */

	if (state == PCI_D3hot)

		pci_dev_d3_sleep(dev);

	else if (state == PCI_D2)

		udelay(PCI_PM_D2_DELAY);



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

	dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;

	if (dev->current_state != state)

		pci_info_ratelimited(dev, "Refused to change power state from %s to %s\n",

				     pci_power_name(dev->current_state),

				     pci_power_name(state));



	if (dev->bus->self)

		pcie_aspm_pm_state_change(dev->bus->self);



	return 0;

}



/**

 * pci_set_power_state - Set the power state of a PCI device

 * @dev: PCI device to handle.