On Tue, Mar 14, 2017 at 2:21 PM, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> msleep() still sleeps 1 jiffy even when told to sleep for zero
> milliseconds. That can end up being 1-2 milliseconds or more. In the cases
> of d3_delay and d3cold_delay, that unnecessarily increases suspend and/or
> resume latencies.
>
> So, do not sleep at all for the respective cases of d3_delay is zero or
> d3cold_delay is zero.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
> drivers/pci/pci.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 7904d02ffdb9..9779483f81fd 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -66,7 +66,8 @@ static void pci_dev_d3_sleep(struct pci_dev *dev)
> if (delay < pci_pm_d3_delay)
> delay = pci_pm_d3_delay;
>
> - msleep(delay);
> + if (delay)
> + msleep(delay);
> }
>
> #ifdef CONFIG_PCI_DOMAINS
> @@ -827,7 +828,8 @@ static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
> * because have already delayed for the bridge.
> */
> if (dev->runtime_d3cold) {
> - msleep(dev->d3cold_delay);
> + if (dev->d3cold_delay)
> + msleep(dev->d3cold_delay);
> /*
> * When powering on a bridge from D3cold, the
> * whole hierarchy may be powered on into
> --
> 1.9.1
>
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