Yep, I am think the same question, is there any other files better to put this function ? How about pci.c ? Thanks, Ethan -----Original Message----- From: Christoph Hellwig <hch@xxxxxxxxxxxxx> Sent: Sunday, September 27, 2020 2:24 PM To: Zhao, Haifeng <haifeng.zhao@xxxxxxxxx> Cc: bhelgaas@xxxxxxxxxx; oohall@xxxxxxxxx; ruscur@xxxxxxxxxx; lukas@xxxxxxxxx; andriy.shevchenko@xxxxxxxxxxxxxxx; stuart.w.hayes@xxxxxxxxx; mr.nuke.me@xxxxxxxxx; mika.westerberg@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Jia, Pei P <pei.p.jia@xxxxxxxxx>; ashok.raj@xxxxxxxxxxxxxxx; Kuppuswamy, Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxx> Subject: Re: [PATCH 1/5 V2] PCI: define a function to check and wait till port finish DPC handling > +#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.