On Tue, 22 Aug 2023 at 13:55, Feiyang Chen <chenfeiyang@xxxxxxxxxxx> wrote:
>
> When the current state is already PCI_D0, pci_power_up() will return
> 0 even though dev->pm_cap is not set. In that case, we should not
> read the PCI_PM_CTRL register in pci_set_full_power_state().
>
> Fixes: e200904b275c ("PCI/PM: Split pci_power_up()")
> Signed-off-by: Feiyang Chen <chenfeiyang@xxxxxxxxxxx>
> ---
> drivers/pci/pci.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 60230da957e0..7e90ab7b47a1 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -1242,9 +1242,6 @@ int pci_power_up(struct pci_dev *dev)
> else
> dev->current_state = state;
>
> - if (state == PCI_D0)
> - return 0;
> -
> return -EIO;
> }
>
> @@ -1302,8 +1299,12 @@ static int pci_set_full_power_state(struct pci_dev *dev)
> int ret;
>
> ret = pci_power_up(dev);
> - if (ret < 0)
> + if (ret < 0) {
> + if (dev->current_state == PCI_D0)
> + return 0;
> +
> return ret;
> + }
>
> pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
> dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
In fuction pci_power_up() there's another if-statement
if (state == PCI_D0)
goto end;
That also will return 0 if need_restore isn't true.
What will happen then?
Would this work?
ret = pci_power_up(dev);
- if (ret < 0)
+ if (ret <= 0)
return ret;
Cheers,
Anders
