Fixed this concern by moving the function to DPC driver and its declaration to pci.h. see v5 Thanks, Ethan On Sun, Sep 27, 2020 at 2:27 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > > +#ifdef CONFIG_PCIE_DPC > > +static inline bool pci_wait_port_outdpc(struct pci_dev *pdev) > > +{ > > + u16 cap = pdev->dpc_cap, status; > > + u16 loop = 0; > > + > > + if (!cap) { > > + pci_WARN_ONCE(pdev, !cap, "No DPC capability initiated\n"); > > + return false; > > + } > > + pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); > > + pci_dbg(pdev, "DPC status %x, cap %x\n", status, cap); > > + while (status & PCI_EXP_DPC_STATUS_TRIGGER && loop < 100) { > > + msleep(10); > > + loop++; > > + pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); > > + } > > + if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) { > > + pci_dbg(pdev, "Out of DPC %x, cost %d ms\n", status, loop*10); > > + return true; > > + } > > + pci_dbg(pdev, "Timeout to wait port out of DPC status\n"); > > + return false; > > +} > > I don't think that there is any good reason to have this as an > inline function.