diff options
author | Rafael J. Wysocki <rjw@sisk.pl> | 2009-03-26 22:51:40 +0100 |
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committer | Rafael J. Wysocki <rjw@sisk.pl> | 2009-03-30 21:46:56 +0200 |
commit | 0e5dd46b761195356065a30611f265adec286d0d (patch) | |
tree | 4ca10dac14ac44789a51048c4ceb3989be175f63 /drivers/pci | |
parent | 931ff68a5a53fa84bcdf9b1b179a80e54e034bd0 (diff) | |
download | linux-0e5dd46b761195356065a30611f265adec286d0d.tar.bz2 |
PCI PM: Introduce __pci_[start|complete]_power_transition() (rev. 2)
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>
Diffstat (limited to 'drivers/pci')
-rw-r--r-- | drivers/pci/pci.c | 69 |
1 files changed, 51 insertions, 18 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 979ceb1d37e8..de54fd643baf 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -540,6 +540,53 @@ 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. * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. @@ -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); - error = 0; - } - } + if (!__pci_complete_power_transition(dev, state)) + error = 0; return error; } |