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/pcie-mediatek.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c index 2f3f974977a3..aa744ccd1a2a 100644 --- a/drivers/pci/controller/pcie-mediatek.c +++ b/drivers/pci/controller/pcie-mediatek.c @@ -369,13 +369,13 @@ static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn, port = mtk_pcie_find_port(bus, devfn); if (!port) { - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return PCIBIOS_DEVICE_NOT_FOUND; } ret = mtk_pcie_hw_rd_cfg(port, bn, devfn, where, size, val); if (ret) - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return ret; } -- 2.25.1