From: Naveen Naidu Date: Thu, 18 Nov 2021 14:03:29 +0000 (+0530) Subject: PCI/DPC: Use PCI_POSSIBLE_ERROR() to check config reads X-Git-Tag: v5.17-rc1~73^2~1^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0242132da26a928801cbb6ab96daf77e7815e084;p=thirdparty%2Fkernel%2Flinux.git PCI/DPC: Use PCI_POSSIBLE_ERROR() to check config reads When config pci_ops.read() can detect failed PCI transactions, the data returned to the CPU is PCI_ERROR_RESPONSE (~0 or 0xffffffff). Obviously a successful PCI config read may *also* return that data if a config register happens to contain ~0, so it doesn't definitively indicate an error unless we know the register cannot contain ~0. Use PCI_POSSIBLE_ERROR() to check the response we get when we read data from hardware. This unifies PCI error response checking and makes error checks consistent and easier to find. Compile tested only. Link: https://lore.kernel.org/r/9b0632f1f183432149f495cf12bdd5a72cc597a4.1637243717.git.naveennaidu479@gmail.com Signed-off-by: Naveen Naidu Signed-off-by: Bjorn Helgaas --- diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index c556e7beafe38..3e9afee02e8d1 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -79,7 +79,7 @@ static bool dpc_completed(struct pci_dev *pdev) u16 status; pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS, &status); - if ((status != 0xffff) && (status & PCI_EXP_DPC_STATUS_TRIGGER)) + if ((!PCI_POSSIBLE_ERROR(status)) && (status & PCI_EXP_DPC_STATUS_TRIGGER)) return false; if (test_bit(PCI_DPC_RECOVERING, &pdev->priv_flags)) @@ -312,7 +312,7 @@ static irqreturn_t dpc_irq(int irq, void *context) pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); - if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || status == (u16)(~0)) + if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || PCI_POSSIBLE_ERROR(status)) return IRQ_NONE; pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,