PCI: designware: Use exact access size in dw_pcie_cfg_read()

dw_pcie_cfg_write() uses the exact 8-, 16-, or 32-bit access size requested, but dw_pcie_cfg_read() previously performed a 32-bit read and masked out the bits requested. Use the exact access size in dw_pcie_cfg_read(). For example, if we want an 8-bit read, use readb() instead of using readl() and masking out the 8 bits we need. This makes it symmetric with dw_pcie_cfg_write(). [bhelgaas: split into separate patch, set *val = 0 in failure case] Signed-off-by: Gabriele Paoloni <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]>
cail · Nov 2, 2015 · c003ca9 · c003ca9
1 parent fa3b7cb
commit c003ca9
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
@@ -82,14 +82,16 @@ static inline struct pcie_port *sys_to_pcie(struct pci_sys_data *sys)
 
 int dw_pcie_cfg_read(void __iomem *addr, int where, int size, u32 *val)
 {
-	*val = readl(addr);
-
-	if (size == 1)
-		*val = (*val >> (8 * (where & 3))) & 0xff;
+	if (size == 4)
+		*val = readl(addr);
 	else if (size == 2)
-		*val = (*val >> (8 * (where & 3))) & 0xffff;
-	else if (size != 4)
+		*val = readw(addr + (where & 2));
+	else if (size == 1)
+		*val = readb(addr + (where & 1));
+	else {
+		*val = 0;
 		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
 
 	return PCIBIOS_SUCCESSFUL;
 }