From: Sajid Dalvi <sdalvi@xxxxxxxxxx> Since the PCI spec requires a 10ms D3Hot delay (defined by PCI_PM_D3HOT_WAIT) and a few of the PCI quirks update the D3Hot delay up to 20ms, let's switch from msleep to usleep_range to improve the delay accuracy. This patch came from Sajid Dalvi <sdalvi@xxxxxxxxxx> in the Pixel 6 kernel tree [1]. Testing on a Pixel 6, found that the 10ms delay for the Exynos PCIe device was on average delaying for 19ms when the spec requires 10ms. Switching from msleep to uslseep_delay therefore decreases the resume time on a Pixel 6 on average by 9ms. [1] https://android.googlesource.com/kernel/gs/+/18a8cad68d8e6d50f339a716a18295e6d987cee3 Signed-off-by: Sajid Dalvi <sdalvi@xxxxxxxxxx> Signed-off-by: Will McVicker <willmcvicker@xxxxxxxxxx> --- drivers/pci/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 95bc329e74c0..5ae5b3c4dc9b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -72,7 +72,8 @@ static void pci_dev_d3_sleep(struct pci_dev *dev) delay = pci_pm_d3hot_delay; if (delay) - msleep(delay); + usleep_range(delay * USEC_PER_MSEC, + (delay + 2) * USEC_PER_MSEC); } bool pci_reset_supported(struct pci_dev *dev) base-commit: 2ae08b36c06ea8df73a79f6b80ff7964e006e9e3 -- 2.37.1.559.g78731f0fdb-goog
