pci: Adjust dm_pci_read_bar32() to return errors correctly

At present if reading a BAR returns 0xffffffff then the value is masked
and a different value is returned. This makes it harder to detect the
problem when debugging.

Update the function to avoid masking in this case.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index ceb64517047653f4052b87f8b6a30a16f93aa3f0..d2e10d6868ab278469c32d049d0e1662ed4718e8 100644 (file)
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1213,7 +1213,14 @@ u32 dm_pci_read_bar32(const struct udevice *dev, int barnum)
 
        bar = PCI_BASE_ADDRESS_0 + barnum * 4;
        dm_pci_read_config32(dev, bar, &addr);
-       if (addr & PCI_BASE_ADDRESS_SPACE_IO)
+
+       /*
+        * If we get an invalid address, return this so that comparisons with
+        * FDT_ADDR_T_NONE work correctly
+        */
+       if (addr == 0xffffffff)
+               return addr;
+       else if (addr & PCI_BASE_ADDRESS_SPACE_IO)
                return addr & PCI_BASE_ADDRESS_IO_MASK;
        else
                return addr & PCI_BASE_ADDRESS_MEM_MASK;