From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com
stable inclusion from linux-4.19.207 commit c5c62f4c936407fb734cae64700f20b68273b059
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[ Upstream commit da9f2150684ea684a7ddd6d7f0e38b2bdf43dcd8 ]
It is inconsistent to return PCI_D0 from pci_target_state() instead of the original target state if 'wakeup' is true and the device cannot signal PME from D0.
This only happens when the device cannot signal PME from the original target state and any shallower power states (including D0) and that case is effectively equivalent to the one in which PME singaling is not supported at all. Since the original target state is returned in the latter case, make the function do that in the former one too.
Link: https://lore.kernel.org/linux-pm/3149540.aeNJFYEL58@kreacher/ Fixes: 666ff6f83e1d ("PCI/PM: Avoid using device_may_wakeup() for runtime PM") Reported-by: Mika Westerberg mika.westerberg@linux.intel.com Reported-by: Utkarsh H Patel utkarsh.h.patel@intel.com Reported-by: Koba Ko koba.ko@canonical.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Reviewed-by: Mika Westerberg mika.westerberg@linux.intel.com Tested-by: Mika Westerberg mika.westerberg@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/pci/pci.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 52618fb1bf64c..e1570b25c58e7 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2346,16 +2346,20 @@ static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup) if (dev->current_state == PCI_D3cold) target_state = PCI_D3cold;
- if (wakeup) { + if (wakeup && dev->pme_support) { + pci_power_t state = target_state; + /* * Find the deepest state from which the device can generate * PME#. */ - if (dev->pme_support) { - while (target_state - && !(dev->pme_support & (1 << target_state))) - target_state--; - } + while (state && !(dev->pme_support & (1 << state))) + state--; + + if (state) + return state; + else if (dev->pme_support & 1) + return PCI_D0; }
return target_state;