On 2/24/2022 9:29 PM, Rajvi Jingar wrote:
> The state of the device is saved during pci_pm_suspend_noirq(), if it has
> not already been saved, regardless of the skip_bus_pm flag value. So
> skip_bus_pm check is removed before saving the device state.
>
> Signed-off-by: Rajvi Jingar <[email protected]>
> Suggested-by: David E. Box <[email protected]>
> ---
> drivers/pci/pci-driver.c | 15 ++-------------
> 1 file changed, 2 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 588588cfda48..ac3f7e1676a9 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -834,20 +834,9 @@ static int pci_pm_suspend_noirq(struct device *dev)
> }
> }
>
> - if (pci_dev->skip_bus_pm) {
> - /*
> - * Either the device is a bridge with a child in D0 below it, or
> - * the function is running for the second time in a row without
> - * going through full resume, which is possible only during
> - * suspend-to-idle in a spurious wakeup case. The device should
> - * be in D0 at this point, but if it is a bridge, it may be
> - * necessary to save its state.
> - */
The comment is outdated, but the role of skip_bus_pm needs to be
explained. It only applies to the bridge with a child in D0 case now,
because the other one has gone away, so I would put a new comment before
the reworked check below.
> - if (!pci_dev->state_saved)
> - pci_save_state(pci_dev);
> - } else if (!pci_dev->state_saved) {
> + if (!pci_dev->state_saved) {
> pci_save_state(pci_dev);
> - if (pci_power_manageable(pci_dev))
For example:
/*
* If the device is a bridge with a child in D0 below it, it needs to
stay in D0, so check
* skip_bus_pm to avoid putting it into a low-power state in that case.
*/
> + if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
> pci_prepare_to_sleep(pci_dev);
> }
>