From 3890c6e1da3146545f9c34611fc94672667a0ce5 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 29 Jul 2021 17:54:28 +0200 Subject: [PATCH] PCI: PM: Avoid forcing PCI_D0 for wakeup reasons inconsistently [ 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 Reported-by: Utkarsh H Patel Reported-by: Koba Ko Signed-off-by: Rafael J. Wysocki Reviewed-by: Mika Westerberg Tested-by: Mika Westerberg Signed-off-by: Sasha Levin --- 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 9e971fffeb6a..d864f964bcae 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2573,16 +2573,20 @@ 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;