An MMIO read from a PCI device that doesn't exist or doesn't respond causes a PCI error. There's no real data to return to satisfy the CPU read, so most hardware fabricates ~0 data. Use SET_PCI_ERROR_RESPONSE() to set the error response, when a faulty read occurs. This helps unify PCI error response checking and make error check consistent and easier to find. Compile tested only. Signed-off-by: Naveen Naidu <naveennaidu479@xxxxxxxxx> --- drivers/pci/controller/dwc/pci-exynos.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pci-exynos.c b/drivers/pci/controller/dwc/pci-exynos.c index c24dab383654..1fdbef184532 100644 --- a/drivers/pci/controller/dwc/pci-exynos.c +++ b/drivers/pci/controller/dwc/pci-exynos.c @@ -217,7 +217,7 @@ static int exynos_pcie_rd_own_conf(struct pci_bus *bus, unsigned int devfn, struct dw_pcie *pci = to_dw_pcie_from_pp(bus->sysdata); if (PCI_SLOT(devfn)) { - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return PCIBIOS_DEVICE_NOT_FOUND; } -- 2.25.1