Add pci_dev_wait() in pci_power_up() before accessing the configuration space of a device for the first time in the system resume sequence. This is to accommodate devices (Ex:- Intel 750 NVMe) that respond with CRS status while they get ready for configuration space access and before they finally start responding with proper values. Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx> --- drivers/pci/pci.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 71b45ce73bf6..7672b9a44bac 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1086,6 +1086,13 @@ int pci_power_up(struct pci_dev *dev) pci_wakeup_bus(dev->subordinate); } + /* + * Wait for those devices (Ex: Intel 750 NVMe) that are not ready yet + * and responding with CRS statuses for the configuration space + * requests. + */ + pci_dev_wait(dev, "Switch to D0", PCIE_RESET_READY_POLL_MS); + return pci_raw_set_power_state(dev, PCI_D0); } -- 2.17.1
