• Rafael J. Wysocki's avatar
    PCI PM: Follow PCI_PM_CTRL_NO_SOFT_RESET during transitions from D3 · f62795f1
    Rafael J. Wysocki authored
    According to the PCI PM specification (PCI Bus Power Management
    Interface Specification, Rev. 1.2, Section 5.4.1) we are supposed to
    reinitialize devices that have PCI_PM_CTRL_NO_SOFT_RESET clear during
    all transitions from PCI_D3hot to PCI_D0, but we only do it if the
    device's current_state field is equal to PCI_UNKNOWN.
    
    This may lead to problems if a device with PCI_PM_CTRL_NO_SOFT_RESET
    unset is put into PCI_D3hot at run time by its driver and
    pci_set_power_state() is used to put it back into PCI_D0, because in
    that case the device will remain uninitialized after
    pci_set_power_state() has returned.  Prevent that from happening by
    modifying pci_raw_set_power_state() to reinitialize devices with
    PCI_PM_CTRL_NO_SOFT_RESET unset during all transitions from D3 to D0.
    
    Cc: stable@kernel.org
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
    f62795f1
pci.c 69.2 KB