]> git.baikalelectronics.ru Git - kernel.git/commit
PCI: Use pci_update_current_state() in pci_enable_device_flags()
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 8 Jul 2021 13:25:06 +0000 (15:25 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Fri, 16 Jul 2021 17:31:35 +0000 (19:31 +0200)
commit5b02fa97e9350609fe9a9ca4e6508fbd156709c5
treee9cf62fdbd4b4a44ed6d04b7b63ee0546d6f7d86
parent01da9c8979f3d24bb75ef7080a8d9915e88dff94
PCI: Use pci_update_current_state() in pci_enable_device_flags()

Updating the current_state field of struct pci_dev the way it is done
in pci_enable_device_flags() before calling do_pci_enable_device() may
not work.  For example, if the given PCI device depends on an ACPI
power resource whose _STA method initially returns 0 ("off"), but the
config space of the PCI device is accessible and the power state
retrieved from the PCI_PM_CTRL register is D0, the current_state
field in the struct pci_dev representing that device will get out of
sync with the power.state of its ACPI companion object and that will
lead to power management issues going forward.

To avoid such issues, make pci_enable_device_flags() call
pci_update_current_state() which takes ACPI device power management
into account, if present, to retrieve the current power state of the
device.

Link: https://lore.kernel.org/lkml/20210314000439.3138941-1-luzmaximilian@gmail.com/
Reported-by: Maximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Maximilian Luz <luzmaximilian@gmail.com>
drivers/pci/pci.c