of: addr: Translate 'dma-ranges' for parent nodes missing 'dma-ranges'

'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 <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Bin Meng 2021-04-30 21:16:58 +08:00 committed by Simon Glass
parent c003d2cd6b
commit 139eaa7a2b

View file

@ -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;
}