Re: [PATCH 2/2] of: addr: Translate 'dma-ranges' for parent nodes missing 'dma-ranges'

[Simon Glass]

On Fri, 26 Feb 2021 at 00:36, Bin Meng  wrote:
>
> '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 
> ---
>
>  drivers/core/of_addr.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Simon Glass 

[PATCH 2/2] of: addr: Translate 'dma-ranges' for parent nodes missing 'dma-ranges'

[Bin Meng]

'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 
---

 drivers/core/of_addr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/core/of_addr.c b/drivers/core/of_addr.c
index 36cdfd3..b9abf90 100644
--- a/drivers/core/of_addr.c
+++ b/drivers/core/of_addr.c
@@ -174,12 +174,12 @@ static int of_translate_one(const struct device_node 
*parent,
u64 offset = OF_BAD_ADDR;
 
ranges = of_get_property(parent, rprop, );
-   if (ranges == NULL) {
+   if (ranges == NULL && strcmp(rprop, "dma-ranges")) {
debug("no ranges; cannot translate\n");
return 1;
}
 
-   if (rlen == 0) {
+   if (ranges == NULL || rlen == 0) {
offset = of_read_number(addr, na);
memset(addr, 0, pna * 4);
debug("empty ranges; 1:1 translation\n");
-- 
2.7.4