3.16.80-rc1 review patch. If anyone has any objections, please let me know.
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From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com
commit 45144d42f299455911cc29366656c7324a3a7c97 upstream.
There is an arbitrary difference between the system resume and runtime resume code paths for PCI devices regarding the delay to apply when switching the devices from D3cold to D0.
Namely, pci_restore_standard_config() used in the runtime resume code path calls pci_set_power_state() which in turn invokes __pci_start_power_transition() to power up the device through the platform firmware and that function applies the transition delay (as per PCI Express Base Specification Revision 2.0, Section 6.6.1). However, pci_pm_default_resume_early() used in the system resume code path calls pci_power_up() which doesn't apply the delay at all and that causes issues to occur during resume from suspend-to-idle on some systems where the delay is required.
Since there is no reason for that difference to exist, modify pci_power_up() to follow pci_set_power_state() more closely and invoke __pci_start_power_transition() from there to call the platform firmware to power up the device (in case that's necessary).
Fixes: db288c9c5f9d ("PCI / PM: restore the original behavior of pci_set_power_state()") Reported-by: Daniel Drake drake@endlessm.com Tested-by: Daniel Drake drake@endlessm.com Link: https://lore.kernel.org/linux-pm/CAD8Lp44TYxrMgPLkHCqF9hv6smEurMXvmmvmtyFhZ6... Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Acked-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/pci/pci.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-)
--- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -657,19 +657,6 @@ void pci_update_current_state(struct pci }
/** - * pci_power_up - Put the given device into D0 forcibly - * @dev: PCI device to power up - */ -void pci_power_up(struct pci_dev *dev) -{ - if (platform_pci_power_manageable(dev)) - platform_pci_set_power_state(dev, PCI_D0); - - pci_raw_set_power_state(dev, PCI_D0); - pci_update_current_state(dev, PCI_D0); -} - -/** * pci_platform_power_transition - Use platform to change device power state * @dev: PCI device to handle. * @state: State to put the device into. @@ -845,6 +832,17 @@ int pci_set_power_state(struct pci_dev * EXPORT_SYMBOL(pci_set_power_state);
/** + * pci_power_up - Put the given device into D0 forcibly + * @dev: PCI device to power up + */ +void pci_power_up(struct pci_dev *dev) +{ + __pci_start_power_transition(dev, PCI_D0); + pci_raw_set_power_state(dev, PCI_D0); + pci_update_current_state(dev, PCI_D0); +} + +/** * pci_choose_state - Choose the power state of a PCI device * @dev: PCI device to be suspended * @state: target sleep state for the whole system. This is the value