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Subject[PATCH 10/11] of/address: Translate 'dma-ranges' for parent nodes missing 'dma-ranges'
Date
'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.

Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
---
drivers/of/address.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index e918001c7798..5b835d332709 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -519,9 +519,13 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
*
* 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")) {
pr_debug("no ranges; cannot translate\n");
return 1;
}
--
2.20.1
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