PCI: mvebu: Fix uninitialized variable in mvebu_get_tgt_attr()

commit 56fab6e189441d714a2bfc8a64f3df9c0749dff7 upstream.

Geert Uytterhoeven reported a warning when building pci-mvebu:

  drivers/pci/host/pci-mvebu.c: In function 'mvebu_get_tgt_attr':
  drivers/pci/host/pci-mvebu.c:887:39: warning: 'rtype' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if (slot == PCI_SLOT(devfn) && type == rtype) {
					 ^

And indeed, the code of mvebu_get_tgt_attr() may lead to the usage of rtype
when being uninitialized, even though it would only happen if we had
entries other than I/O space and 32 bits memory space.

This commit fixes that by simply skipping the current DT range being
considered, if it doesn't match the resource type we're looking for.

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 483d9ad..9773667 100644 (file)
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -855,7 +855,7 @@ static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
        rangesz = pna + na + ns;
        nranges = rlen / sizeof(__be32) / rangesz;
 
-       for (i = 0; i < nranges; i++) {
+       for (i = 0; i < nranges; i++, range += rangesz) {
                u32 flags = of_read_number(range, 1);
                u32 slot = of_read_number(range + 1, 1);
                u64 cpuaddr = of_read_number(range + na, pna);
@@ -865,14 +865,14 @@ static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
                        rtype = IORESOURCE_IO;
                else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
                        rtype = IORESOURCE_MEM;
+               else
+                       continue;
 
                if (slot == PCI_SLOT(devfn) && type == rtype) {
                        *tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
                        *attr = DT_CPUADDR_TO_ATTR(cpuaddr);
                        return 0;
                }
-
-               range += rangesz;
        }
 
        return -ENOENT;