'dma-ranges' frequently exists without parent nodes having 'dma-ranges'.
While this is an error for 'ranges', this is fine because DMA capable
devices always have a translatable DMA address. Also, with no
'dma-ranges' at all, the assumption is that DMA addresses are 1:1 with
no restrictions unless perhaps the device itself has implicit
restrictions.

This keeps in sync with Linux kernel commit:

  81db12ee15cb: of/address: Translate 'dma-ranges' for parent nodes missing 
'dma-ranges'

Signed-off-by: Bin Meng <[email protected]>
Reviewed-by: Simon Glass <[email protected]>

---

Changes in v2:
- rebase on top of Dario's revert patch:
  
http://patchwork.ozlabs.org/project/uboot/patch/[email protected]/
- drop commit "of: addr: Abort address translation for parent nodes missing 
'ranges'",
  as the revert patch restores the abort behavior

 drivers/core/of_addr.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/core/of_addr.c b/drivers/core/of_addr.c
index 9b77308182..a3af48fd88 100644
--- a/drivers/core/of_addr.c
+++ b/drivers/core/of_addr.c
@@ -192,9 +192,13 @@ static int of_translate_one(const struct device_node 
*parent,
         *
         * As far as we know, this damage only exists on Apple machines, so
         * This code is only enabled on powerpc. --gcl
+        *
+        * This quirk also applies for 'dma-ranges' which frequently exist in
+        * child nodes without 'dma-ranges' in the parent nodes. --RobH
         */
        ranges = of_get_property(parent, rprop, &rlen);
-       if (ranges == NULL && !of_empty_ranges_quirk(parent)) {
+       if (ranges == NULL && !of_empty_ranges_quirk(parent) &&
+           strcmp(rprop, "dma-ranges")) {
                debug("no ranges; cannot translate\n");
                return 1;
        }
-- 
2.25.1

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