Re: [PATCH 1/6] PCI/PM: Apply D2 delay as milliseconds, not microseconds

From: Rafael J. Wysocki
Date: Mon Nov 04 2019 - 05:29:19 EST


On Fri, Nov 1, 2019 at 9:46 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>
> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> PCI_PM_D2_DELAY is defined as 200, which is milliseconds, but previously we
> used udelay(), which only waited for 200 microseconds. Use msleep()
> instead so we wait the correct amount of time. See PCIe r5.0, sec 5.9.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

> ---
> drivers/pci/pci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index e7982af9a5d8..cd96874ae76d 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -886,7 +886,7 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
> if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
> pci_dev_d3_sleep(dev);
> else if (state == PCI_D2 || dev->current_state == PCI_D2)
> - udelay(PCI_PM_D2_DELAY);
> + msleep(PCI_PM_D2_DELAY);
>
> pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
> dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
> --
> 2.24.0.rc1.363.gb1bccd3e3d-goog
>