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PCI PM: Introduce __pci_[start|complete]_power_transition() (rev. 2)

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The radeonfb driver needs to program the device's PMCSR directly due
to some quirky hardware it has to handle (see
http://bugzilla.kernel.org/show_bug.cgi?id=12846 for details) and
after doing that it needs to call the platform (usually ACPI) to
finish the power transition of the device.  Currently it uses
pci_set_power_state() for this purpose, however making a specific
assumption about the internal behavior of this function, which has
changed recently so that this assumption is no longer satisfied.
For this reason, introduce __pci_complete_power_transition() that may
be called by the radeonfb driver to complete the power transition of
the device.  For symmetry, introduce __pci_start_power_transition().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Rafael J. Wysocki 2009-03-26 22:51:40 +01:00
parent 931ff68a5a
commit 0e5dd46b76
2 changed files with 52 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
drivers/pci/pci.c
View File

@ -539,6 +539,53 @@ void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
}
}
/**
* pci_platform_power_transition - Use platform to change device power state
* @dev: PCI device to handle.
* @state: State to put the device into.
*/
static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
{
int error;
if (platform_pci_power_manageable(dev)) {
error = platform_pci_set_power_state(dev, state);
if (!error)
pci_update_current_state(dev, state);
} else {
error = -ENODEV;
/* Fall back to PCI_D0 if native PM is not supported */
pci_update_current_state(dev, PCI_D0);
}
return error;
}
/**
* __pci_start_power_transition - Start power transition of a PCI device
* @dev: PCI device to handle.
* @state: State to put the device into.
*/
static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
{
if (state == PCI_D0)
pci_platform_power_transition(dev, PCI_D0);
}
/**
* __pci_complete_power_transition - Complete power transition of a PCI device
* @dev: PCI device to handle.
* @state: State to put the device into.
*
* This function should not be called directly by device drivers.
*/
int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
{
return state > PCI_D0 ?
pci_platform_power_transition(dev, state) : -EINVAL;
}
EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
/**
* pci_set_power_state - Set the power state of a PCI device
* @dev: PCI device to handle.
@ -575,16 +622,8 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
if (dev->current_state == state)
return 0;
if (state == PCI_D0) {
/*
* Allow the platform to change the state, for example via ACPI
* _PR0, _PS0 and some such, but do not trust it.
*/
int ret = platform_pci_power_manageable(dev) ?
platform_pci_set_power_state(dev, PCI_D0) : 0;
if (!ret)
pci_update_current_state(dev, PCI_D0);
}
__pci_start_power_transition(dev, state);
/* This device is quirked not to be put into D3, so
don't put it in D3 */
if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
@ -592,14 +631,8 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
error = pci_raw_set_power_state(dev, state);
if (state > PCI_D0 && platform_pci_power_manageable(dev)) {
/* Allow the platform to finalize the transition */
int ret = platform_pci_set_power_state(dev, state);
if (!ret) {
pci_update_current_state(dev, state);
if (!__pci_complete_power_transition(dev, state))
error = 0;
}
}
return error;
}

1
include/linux/pci.h
View File

@ -689,6 +689,7 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size);
/* Power management related routines */
int pci_save_state(struct pci_dev *dev);
int pci_restore_state(struct pci_dev *dev);
int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state);
int pci_set_power_state(struct pci_dev *dev, pci_power_t state);
pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state);
bool pci_pme_capable(struct pci_dev *dev, pci_power_t state);