Re: [PATCH v2 1/6] PCI: Stop setting cached power state to "unknown" on unbind

[Rafael J. Wysocki]

On Mon, Apr 27, 2026 at 10:50 PM Mario Limonciello (AMD)
<superm1@xxxxxxxxxx> wrote:
>
> From: Lukas Wunner <lukas@xxxxxxxxx>
>
> When a PCI device is unbound from its driver, pci_device_remove() sets the
> cached power state in pci_dev->current_state to PCI_UNKNOWN.  This was
> introduced by commit 2449e06a5696 ("PCI: reset pci device state to unknown
> state for resume") to invalidate the cached power state in case the system
> is subsequently put to sleep.
>
> For bound devices, the cached power state is set to PCI_UNKNOWN in
> pci_pm_suspend_noirq(), immediately before entering system sleep.
>
> Extend to unbound devices for consistency.
>
> This obviates the need to change the cached power state on unbind, so stop
> doing so.
>
> Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
> Reviewed-by: Mario Limonciello (AMD) <superm1@xxxxxxxxxx>

Reviewed-by: Rafael J. Wysocki (Intel) <rafael@xxxxxxxxxx>

> ---
>  drivers/pci/pci-driver.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index d10ece0889f0f..2bfefd8db5260 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -512,13 +512,6 @@ static void pci_device_remove(struct device *dev)
>         /* Undo the runtime PM settings in local_pci_probe() */
>         pm_runtime_put_sync(dev);
>
> -       /*
> -        * If the device is still on, set the power state as "unknown",
> -        * since it might change by the next time we load the driver.
> -        */
> -       if (pci_dev->current_state == PCI_D0)
> -               pci_dev->current_state = PCI_UNKNOWN;
> -
>         /*
>          * We would love to complain here if pci_dev->is_enabled is set, that
>          * the driver should have called pci_disable_device(), but the
> @@ -893,7 +886,7 @@ static int pci_pm_suspend_noirq(struct device *dev)
>
>         if (!pm) {
>                 pci_save_state(pci_dev);
> -               goto Fixup;
> +               goto set_unknown;
>         }
>
>         if (pm->suspend_noirq) {
> @@ -945,6 +938,7 @@ static int pci_pm_suspend_noirq(struct device *dev)
>                 goto Fixup;
>         }
>
> +set_unknown:
>         pci_pm_set_unknown_state(pci_dev);
>
>         /*
> --
> 2.53.0
>