[RFC][PATCH][6/8] PCI PM: Use pci_set_power_state during early resume

Rafael J. Wysocki
2009-03-07T10:25:28Z

From: Rafael J. Wysocki <rjw@sisk.pl>

Once we have allowed timer interrupts to be enabled during the early
phase of resuming devices, we are now able to use the generic
pci_set_power_state() to put PCI devices into D0 at that time. Then,
the platform-specific PM code will have a chance to handle devices
that don't implement the native PCI PM or that require some
additional, platform-specific operations to be carried out to power
them up. Also, by doing this we can simplify the code quite a bit.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/pci/pci.c | 48 +++++++++---------------------------------------
1 file changed, 9 insertions(+), 39 deletions(-)

Index: linux-2.6/drivers/pci/pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci.c
+++ linux-2.6/drivers/pci/pci.c
@@ -426,7 +426,6 @@ static inline int platform_pci_sleep_wak
* given PCI device
* @dev: PCI device to handle.
* @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
- * @wait: If 'true', wait for the device to change its power state
*
* RETURN VALUE:
* -EINVAL if the requested state is invalid.
@@ -435,8 +434,7 @@ static inline int platform_pci_sleep_wak
* 0 if device already is in the requested state.
* 0 if device's power state has been successfully changed.
*/
-static int
-pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state, bool wait)
+static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
{
u16 pmcsr;
bool need_restore = false;
@@ -481,10 +479,8 @@ pci_raw_set_power_state(struct pci_dev *
break;
case PCI_UNKNOWN: /* Boot-up */
if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
- && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) {
+ && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
need_restore = true;
- wait = true;
- }
/* Fall-through: force to D0 */
default:
pmcsr = 0;
@@ -494,9 +490,6 @@ pci_raw_set_power_state(struct pci_dev *
/* enter specified state */
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);

- if (!wait)
- return 0;
-
/* Mandatory power management transition delays */
/* see PCI PM 1.1 5.6.1 table 18 */
if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
@@ -521,7 +514,7 @@ pci_raw_set_power_state(struct pci_dev *
if (need_restore)
pci_restore_bars(dev);

- if (wait && dev->bus->self)
+ if (dev->bus->self)
pcie_aspm_pm_state_change(dev->bus->self);

return 0;
@@ -591,7 +584,7 @@ int pci_set_power_state(struct pci_dev *
if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
return 0;

- error = pci_raw_set_power_state(dev, state, true);
+ error = pci_raw_set_power_state(dev, state);

if (state > PCI_D0 && platform_pci_power_manageable(dev)) {
/* Allow the platform to finalize the transition */
@@ -1390,37 +1383,14 @@ void pci_allocate_cap_save_buffers(struc
*/
int pci_restore_standard_config(struct pci_dev *dev)
{
- pci_power_t prev_state;
- int error;
-
- pci_update_current_state(dev, PCI_D0);
-
- prev_state = dev->current_state;
- if (prev_state == PCI_D0)
- goto Restore;
-
- error = pci_raw_set_power_state(dev, PCI_D0, false);
- if (error)
- return error;
+ pci_update_current_state(dev, PCI_UNKNOWN);

- /*
- * This assumes that we won't get a bus in B2 or B3 from the BIOS, but
- * we've made this assumption forever and it appears to be universally
- * satisfied.
- */
- switch(prev_state) {
- case PCI_D3cold:
- case PCI_D3hot:
- mdelay(pci_pm_d3_delay);
- break;
- case PCI_D2:
- udelay(PCI_PM_D2_DELAY);
- break;
+ if (dev->current_state != PCI_D0) {
+ int error = pci_set_power_state(dev, PCI_D0);
+ if (error)
+ return error;
}

- pci_update_current_state(dev, PCI_D0);
-
- Restore:
return dev->state_saved ? pci_restore_state(dev) : 0;
}