target/linux/bcm27xx/patches-5.4/950-0438-of-address-Translate-dma-ranges-for-parent-nodes-mis.patch

   1 From 39f5d9e883393e32938eac45b564f74afde8a942 Mon Sep 17 00:00:00 2001
   2 From: Rob Herring <robh@kernel.org>
   3 Date: Wed, 4 Sep 2019 11:43:30 +0100
   4 Subject: [PATCH] of/address: Translate 'dma-ranges' for parent nodes
   5  missing 'dma-ranges'
   6
   7 commit 81db12ee15cb83926e290a8a3654a2dfebc80935 upstream.
   8
   9 'dma-ranges' frequently exists without parent nodes having 'dma-ranges'.
  10 While this is an error for 'ranges', this is fine because DMA capable
  11 devices always have a translatable DMA address. Also, with no
  12 'dma-ranges' at all, the assumption is that DMA addresses are 1:1 with
  13 no restrictions unless perhaps the device itself has implicit
  14 restrictions.
  15
  16 Cc: Robin Murphy <robin.murphy@arm.com>
  17 Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
  18 Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
  19 Signed-off-by: Rob Herring <robh@kernel.org>
  20 ---
  21  drivers/of/address.c | 6 +++++-
  22  1 file changed, 5 insertions(+), 1 deletion(-)
  23
  24 --- a/drivers/of/address.c
  25 +++ b/drivers/of/address.c
  26 @@ -519,9 +519,13 @@ static int of_translate_one(struct devic
  27          *
  28          * As far as we know, this damage only exists on Apple machines, so
  29          * This code is only enabled on powerpc. --gcl
  30 +        *
  31 +        * This quirk also applies for 'dma-ranges' which frequently exist in
  32 +        * child nodes without 'dma-ranges' in the parent nodes. --RobH
  33          */
  34         ranges = of_get_property(parent, rprop, &rlen);
  35 -       if (ranges == NULL && !of_empty_ranges_quirk(parent)) {
  36 +       if (ranges == NULL && !of_empty_ranges_quirk(parent) &&
  37 +           strcmp(rprop, "dma-ranges")) {
  38                 pr_debug("no ranges; cannot translate\n");
  39                 return 1;
  40         }