* [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit
@ 2015-07-23 16:51 Stephen Warren
2015-07-27 17:13 ` Simon Glass
0 siblings, 1 reply; 6+ messages in thread
From: Stephen Warren @ 2015-07-23 16:51 UTC (permalink / raw)
To: u-boot
From: Thierry Reding <treding@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
Simon,
When Thierry first posted this patch, you responded:
> > + parent = fdt_parent_offset(blob, node);
>
> This function is very slow as it must scan the whole tree. Can we
> instead pass in the parent node?
I don't think that's possible in general. This function is called from
fdtdec_get_addr(), and it's easy to find call sites of that function that
don't have the parent node available. IIRC, the first couple of example I
found scan the DT for a node with a certain compatible value, or look up
nodes via aliases, rather than being called while parsing the DT in a
top-down tree-like fashion, where the parent node is easily available. I
didn't do an exhaustive search after I found a few problematic cases.
> Also, how about (in addition) a
> version of this function that works for devices? Like:
>
> device_get_addr_size(struct udevice *dev, ...)
>
> so that it can handle this for you.
That sounds like a separate patch?
Equally, I see that struct udevice contains an of_offset field, but no
parent_of_offset or similar. There is a struct udevice *parent though;
is the struct udevice hierarchy guaranteed to 100% match the DT
hierarchy? I know this isn't necessarily guaranteed in Linux's device
model for example.
As such, this patch seems OK to me as-is.
---
lib/fdtdec.c | 56 ++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 36 insertions(+), 20 deletions(-)
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 9c6b3619da24..56e72eafaade 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -88,29 +88,45 @@ const char *fdtdec_get_compatible(enum fdt_compat_id id)
fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
const char *prop_name, fdt_size_t *sizep)
{
- const fdt_addr_t *cell;
- int len;
+ const fdt32_t *ptr, *end;
+ int parent, na, ns, len;
+ fdt_addr_t addr;
debug("%s: %s: ", __func__, prop_name);
- cell = fdt_getprop(blob, node, prop_name, &len);
- if (cell && ((!sizep && len == sizeof(fdt_addr_t)) ||
- len == sizeof(fdt_addr_t) * 2)) {
- fdt_addr_t addr = fdt_addr_to_cpu(*cell);
- if (sizep) {
- const fdt_size_t *size;
-
- size = (fdt_size_t *)((char *)cell +
- sizeof(fdt_addr_t));
- *sizep = fdt_size_to_cpu(*size);
- debug("addr=%08lx, size=%llx\n",
- (ulong)addr, (u64)*sizep);
- } else {
- debug("%08lx\n", (ulong)addr);
- }
- return addr;
+
+ parent = fdt_parent_offset(blob, node);
+ if (parent < 0) {
+ debug("(no parent found)\n");
+ return FDT_ADDR_T_NONE;
}
- debug("(not found)\n");
- return FDT_ADDR_T_NONE;
+
+ na = fdt_address_cells(blob, parent);
+ ns = fdt_size_cells(blob, parent);
+
+ ptr = fdt_getprop(blob, node, prop_name, &len);
+ if (!ptr) {
+ debug("(not found)\n");
+ return FDT_ADDR_T_NONE;
+ }
+
+ end = ptr + len / sizeof(*ptr);
+
+ if (ptr + na + ns > end) {
+ debug("(not enough data: expected %d bytes, got %d bytes)\n",
+ (na + ns) * 4, len);
+ return FDT_ADDR_T_NONE;
+ }
+
+ addr = fdtdec_get_number(ptr, na);
+
+ if (sizep) {
+ *sizep = fdtdec_get_number(ptr + na, ns);
+ debug("addr=%pa, size=%pa\n", &addr, sizep);
+ } else {
+ debug("%pa\n", &addr);
+ }
+
+ return addr;
}
fdt_addr_t fdtdec_get_addr(const void *blob, int node,
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit
2015-07-23 16:51 [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit Stephen Warren
@ 2015-07-27 17:13 ` Simon Glass
2015-08-02 21:27 ` Simon Glass
0 siblings, 1 reply; 6+ messages in thread
From: Simon Glass @ 2015-07-27 17:13 UTC (permalink / raw)
To: u-boot
Hi,
On 23 July 2015 at 10:51, Stephen Warren <swarren@wwwdotorg.org> wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> Signed-off-by: Tom Warren <twarren@nvidia.com>
> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> ---
> Simon,
>
> When Thierry first posted this patch, you responded:
>
>> > + parent = fdt_parent_offset(blob, node);
>>
>> This function is very slow as it must scan the whole tree. Can we
>> instead pass in the parent node?
>
> I don't think that's possible in general. This function is called from
> fdtdec_get_addr(), and it's easy to find call sites of that function that
> don't have the parent node available. IIRC, the first couple of example I
> found scan the DT for a node with a certain compatible value, or look up
> nodes via aliases, rather than being called while parsing the DT in a
> top-down tree-like fashion, where the parent node is easily available. I
> didn't do an exhaustive search after I found a few problematic cases.
>
>> Also, how about (in addition) a
>> version of this function that works for devices? Like:
>>
>> device_get_addr_size(struct udevice *dev, ...)
>>
>> so that it can handle this for you.
>
> That sounds like a separate patch?
Yes, but I think we should get it in there so that people don't start
using this (wildly inefficient) function when they don't need to. I
think by passing in the parent node we force people to think about the
cost.
Yes the driver model function can be a separate patch, but let's get
it in at about the same time. We have dev_get_addr() so could have
dev_get_addr_size().
>
> Equally, I see that struct udevice contains an of_offset field, but no
> parent_of_offset or similar. There is a struct udevice *parent though;
> is the struct udevice hierarchy guaranteed to 100% match the DT
> hierarchy? I know this isn't necessarily guaranteed in Linux's device
> model for example.
Yes it is 100% guaranteed, so dev->parent->of_offset will do the right thing.
>
> As such, this patch seems OK to me as-is.
> ---
> lib/fdtdec.c | 56 ++++++++++++++++++++++++++++++++++++--------------------
> 1 file changed, 36 insertions(+), 20 deletions(-)
>
> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
> index 9c6b3619da24..56e72eafaade 100644
> --- a/lib/fdtdec.c
> +++ b/lib/fdtdec.c
> @@ -88,29 +88,45 @@ const char *fdtdec_get_compatible(enum fdt_compat_id id)
> fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
> const char *prop_name, fdt_size_t *sizep)
> {
> - const fdt_addr_t *cell;
> - int len;
> + const fdt32_t *ptr, *end;
> + int parent, na, ns, len;
> + fdt_addr_t addr;
>
> debug("%s: %s: ", __func__, prop_name);
> - cell = fdt_getprop(blob, node, prop_name, &len);
> - if (cell && ((!sizep && len == sizeof(fdt_addr_t)) ||
> - len == sizeof(fdt_addr_t) * 2)) {
> - fdt_addr_t addr = fdt_addr_to_cpu(*cell);
> - if (sizep) {
> - const fdt_size_t *size;
> -
> - size = (fdt_size_t *)((char *)cell +
> - sizeof(fdt_addr_t));
> - *sizep = fdt_size_to_cpu(*size);
> - debug("addr=%08lx, size=%llx\n",
> - (ulong)addr, (u64)*sizep);
> - } else {
> - debug("%08lx\n", (ulong)addr);
> - }
> - return addr;
> +
> + parent = fdt_parent_offset(blob, node);
> + if (parent < 0) {
> + debug("(no parent found)\n");
> + return FDT_ADDR_T_NONE;
> }
> - debug("(not found)\n");
> - return FDT_ADDR_T_NONE;
> +
> + na = fdt_address_cells(blob, parent);
> + ns = fdt_size_cells(blob, parent);
> +
> + ptr = fdt_getprop(blob, node, prop_name, &len);
> + if (!ptr) {
> + debug("(not found)\n");
> + return FDT_ADDR_T_NONE;
> + }
> +
> + end = ptr + len / sizeof(*ptr);
> +
> + if (ptr + na + ns > end) {
> + debug("(not enough data: expected %d bytes, got %d bytes)\n",
> + (na + ns) * 4, len);
> + return FDT_ADDR_T_NONE;
> + }
> +
> + addr = fdtdec_get_number(ptr, na);
> +
> + if (sizep) {
> + *sizep = fdtdec_get_number(ptr + na, ns);
> + debug("addr=%pa, size=%pa\n", &addr, sizep);
> + } else {
> + debug("%pa\n", &addr);
> + }
> +
> + return addr;
> }
>
> fdt_addr_t fdtdec_get_addr(const void *blob, int node,
> --
> 1.9.1
>
Regards,
SImon
^ permalink raw reply [flat|nested] 6+ messages in thread* [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit
2015-07-27 17:13 ` Simon Glass
@ 2015-08-02 21:27 ` Simon Glass
2015-08-04 14:26 ` Thierry Reding
0 siblings, 1 reply; 6+ messages in thread
From: Simon Glass @ 2015-08-02 21:27 UTC (permalink / raw)
To: u-boot
Hi,
On 27 July 2015 at 11:13, Simon Glass <sjg@chromium.org> wrote:
> Hi,
>
> On 23 July 2015 at 10:51, Stephen Warren <swarren@wwwdotorg.org> wrote:
>> From: Thierry Reding <treding@nvidia.com>
>>
>> Signed-off-by: Thierry Reding <treding@nvidia.com>
>> Signed-off-by: Tom Warren <twarren@nvidia.com>
>> Signed-off-by: Stephen Warren <swarren@nvidia.com>
>> ---
>> Simon,
>>
>> When Thierry first posted this patch, you responded:
>>
>>> > + parent = fdt_parent_offset(blob, node);
>>>
>>> This function is very slow as it must scan the whole tree. Can we
>>> instead pass in the parent node?
>>
>> I don't think that's possible in general. This function is called from
>> fdtdec_get_addr(), and it's easy to find call sites of that function that
>> don't have the parent node available. IIRC, the first couple of example I
>> found scan the DT for a node with a certain compatible value, or look up
>> nodes via aliases, rather than being called while parsing the DT in a
>> top-down tree-like fashion, where the parent node is easily available. I
>> didn't do an exhaustive search after I found a few problematic cases.
>>
>>> Also, how about (in addition) a
>>> version of this function that works for devices? Like:
>>>
>>> device_get_addr_size(struct udevice *dev, ...)
>>>
>>> so that it can handle this for you.
>>
>> That sounds like a separate patch?
>
> Yes, but I think we should get it in there so that people don't start
> using this (wildly inefficient) function when they don't need to. I
> think by passing in the parent node we force people to think about the
> cost.
>
> Yes the driver model function can be a separate patch, but let's get
> it in at about the same time. We have dev_get_addr() so could have
> dev_get_addr_size().
>
>>
>> Equally, I see that struct udevice contains an of_offset field, but no
>> parent_of_offset or similar. There is a struct udevice *parent though;
>> is the struct udevice hierarchy guaranteed to 100% match the DT
>> hierarchy? I know this isn't necessarily guaranteed in Linux's device
>> model for example.
>
> Yes it is 100% guaranteed, so dev->parent->of_offset will do the right thing.
>
>>
>> As such, this patch seems OK to me as-is.
>> ---
>> lib/fdtdec.c | 56 ++++++++++++++++++++++++++++++++++++--------------------
>> 1 file changed, 36 insertions(+), 20 deletions(-)
>>
This patch has been applied. I'm going to post a revert of this patch.
Please can you take a look at the comments above? In particular this
function is called from dev_get_addr() which is a core driver model
function. It needs to be fast - and in fact dev_get_addr() already has
access to the parent node.
Also looking a bit closer this patch does a lot more than 'fix it for
64-bit'. A commit message would be useful to explain what problems it
is fixing, etc.
Another point is that fdt_addr_t and fdt_size_t are supposed to match
the address size used in the device tree. Is that not the case with
Tegra210?
>> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
>> index 9c6b3619da24..56e72eafaade 100644
>> --- a/lib/fdtdec.c
>> +++ b/lib/fdtdec.c
>> @@ -88,29 +88,45 @@ const char *fdtdec_get_compatible(enum fdt_compat_id id)
>> fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
>> const char *prop_name, fdt_size_t *sizep)
>> {
>> - const fdt_addr_t *cell;
>> - int len;
>> + const fdt32_t *ptr, *end;
>> + int parent, na, ns, len;
>> + fdt_addr_t addr;
>>
>> debug("%s: %s: ", __func__, prop_name);
>> - cell = fdt_getprop(blob, node, prop_name, &len);
>> - if (cell && ((!sizep && len == sizeof(fdt_addr_t)) ||
>> - len == sizeof(fdt_addr_t) * 2)) {
>> - fdt_addr_t addr = fdt_addr_to_cpu(*cell);
>> - if (sizep) {
>> - const fdt_size_t *size;
>> -
>> - size = (fdt_size_t *)((char *)cell +
>> - sizeof(fdt_addr_t));
>> - *sizep = fdt_size_to_cpu(*size);
>> - debug("addr=%08lx, size=%llx\n",
>> - (ulong)addr, (u64)*sizep);
>> - } else {
>> - debug("%08lx\n", (ulong)addr);
>> - }
>> - return addr;
>> +
>> + parent = fdt_parent_offset(blob, node);
>> + if (parent < 0) {
>> + debug("(no parent found)\n");
>> + return FDT_ADDR_T_NONE;
>> }
>> - debug("(not found)\n");
>> - return FDT_ADDR_T_NONE;
>> +
>> + na = fdt_address_cells(blob, parent);
>> + ns = fdt_size_cells(blob, parent);
>> +
>> + ptr = fdt_getprop(blob, node, prop_name, &len);
>> + if (!ptr) {
>> + debug("(not found)\n");
>> + return FDT_ADDR_T_NONE;
>> + }
>> +
>> + end = ptr + len / sizeof(*ptr);
>> +
>> + if (ptr + na + ns > end) {
>> + debug("(not enough data: expected %d bytes, got %d bytes)\n",
>> + (na + ns) * 4, len);
>> + return FDT_ADDR_T_NONE;
>> + }
>> +
>> + addr = fdtdec_get_number(ptr, na);
>> +
>> + if (sizep) {
>> + *sizep = fdtdec_get_number(ptr + na, ns);
>> + debug("addr=%pa, size=%pa\n", &addr, sizep);
>> + } else {
>> + debug("%pa\n", &addr);
>> + }
>> +
>> + return addr;
>> }
>>
>> fdt_addr_t fdtdec_get_addr(const void *blob, int node,
>> --
>> 1.9.1
>>
Regards,
Simon
^ permalink raw reply [flat|nested] 6+ messages in thread* [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit
2015-08-02 21:27 ` Simon Glass
@ 2015-08-04 14:26 ` Thierry Reding
2015-08-04 15:23 ` Stephen Warren
0 siblings, 1 reply; 6+ messages in thread
From: Thierry Reding @ 2015-08-04 14:26 UTC (permalink / raw)
To: u-boot
On Sun, Aug 02, 2015 at 03:27:53PM -0600, Simon Glass wrote:
> Hi,
>
> On 27 July 2015 at 11:13, Simon Glass <sjg@chromium.org> wrote:
> > Hi,
> >
> > On 23 July 2015 at 10:51, Stephen Warren <swarren@wwwdotorg.org> wrote:
> >> From: Thierry Reding <treding@nvidia.com>
> >>
> >> Signed-off-by: Thierry Reding <treding@nvidia.com>
> >> Signed-off-by: Tom Warren <twarren@nvidia.com>
> >> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> >> ---
> >> Simon,
> >>
> >> When Thierry first posted this patch, you responded:
> >>
> >>> > + parent = fdt_parent_offset(blob, node);
> >>>
> >>> This function is very slow as it must scan the whole tree. Can we
> >>> instead pass in the parent node?
> >>
> >> I don't think that's possible in general. This function is called from
> >> fdtdec_get_addr(), and it's easy to find call sites of that function that
> >> don't have the parent node available. IIRC, the first couple of example I
> >> found scan the DT for a node with a certain compatible value, or look up
> >> nodes via aliases, rather than being called while parsing the DT in a
> >> top-down tree-like fashion, where the parent node is easily available. I
> >> didn't do an exhaustive search after I found a few problematic cases.
> >>
> >>> Also, how about (in addition) a
> >>> version of this function that works for devices? Like:
> >>>
> >>> device_get_addr_size(struct udevice *dev, ...)
> >>>
> >>> so that it can handle this for you.
> >>
> >> That sounds like a separate patch?
> >
> > Yes, but I think we should get it in there so that people don't start
> > using this (wildly inefficient) function when they don't need to. I
> > think by passing in the parent node we force people to think about the
> > cost.
> >
> > Yes the driver model function can be a separate patch, but let's get
> > it in at about the same time. We have dev_get_addr() so could have
> > dev_get_addr_size().
> >
> >>
> >> Equally, I see that struct udevice contains an of_offset field, but no
> >> parent_of_offset or similar. There is a struct udevice *parent though;
> >> is the struct udevice hierarchy guaranteed to 100% match the DT
> >> hierarchy? I know this isn't necessarily guaranteed in Linux's device
> >> model for example.
> >
> > Yes it is 100% guaranteed, so dev->parent->of_offset will do the right thing.
> >
> >>
> >> As such, this patch seems OK to me as-is.
> >> ---
> >> lib/fdtdec.c | 56 ++++++++++++++++++++++++++++++++++++--------------------
> >> 1 file changed, 36 insertions(+), 20 deletions(-)
> >>
>
> This patch has been applied. I'm going to post a revert of this patch.
> Please can you take a look at the comments above? In particular this
> function is called from dev_get_addr() which is a core driver model
> function. It needs to be fast - and in fact dev_get_addr() already has
> access to the parent node.
Perhaps this could be fixed by doing passing in the parent as an
optional argument and then do something like this:
if (parent < 0) {
parent = fdt_parent_offset(blob, node);
if (parent < 0) {
...
}
}
In that case callers that have access to the parent node already can
pass it in, but others can simply pass in -1 and have the function do
the lookup.
> Also looking a bit closer this patch does a lot more than 'fix it for
> 64-bit'. A commit message would be useful to explain what problems it
> is fixing, etc.
>
> Another point is that fdt_addr_t and fdt_size_t are supposed to match
> the address size used in the device tree. Is that not the case with
> Tegra210?
You can't assume that #address-cells and #size-cells will be 2 for all
64-bit platforms. Some may well go with #address-cells = 1 and #size-
cells = 1, and I've seen others do #address-cells = 2 and #size-cells =
1. All of these combinations are perfectly valid.
As such, fdt_addr_t and fdt_size_t make sense only if they are the
maximum that the architecture can support. Even so an address could
technically be larger than that, if it's behind a translated bus, for
example.
So what this does is really fix parsing of address and size cells in the
general case, though it would still fail for values of #address-cells or
#size-cells bigger than 2 (because we don't have a datatype that would
be able to contain such large values).
Note that there's also still a corner case that this doesn't handle. The
DT specification states, if I remember correctly, that #address-cells
and #size-cells are inherited. That means with the current code we will
wrongly parse something like this:
/ {
...
#address-cells = <1>;
#size-cells = <1>;
...
bus at XXXXXXXX {
...
device at XXXXXXXX {
...
reg = <0xXXXXXXXX 0x1000>;
...
};
...
};
...
};
According to the DT specification the bus at XXXXXXXX node would inherit
#address-cells = <1> and #size-cells = <1> from the root node. However
with libfdt what really happens is that since bus at XXXXXXXX does not have
either property it will default to 2 in both cases. I'm not sure if this
really is a problem. Typically nodes are not nested that deeply, or if
they are then, typically, they explicitly contain #address-cells and
#size-cells properties.
Thierry
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^ permalink raw reply [flat|nested] 6+ messages in thread* [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit
2015-08-04 14:26 ` Thierry Reding
@ 2015-08-04 15:23 ` Stephen Warren
2015-08-04 15:36 ` Thierry Reding
0 siblings, 1 reply; 6+ messages in thread
From: Stephen Warren @ 2015-08-04 15:23 UTC (permalink / raw)
To: u-boot
On 08/04/2015 08:26 AM, Thierry Reding wrote:
... [ discussion of new fdtdec_get_addr_size() implementation]
> So what this does is really fix parsing of address and size cells in the
> general case, though it would still fail for values of #address-cells or
> #size-cells bigger than 2 (because we don't have a datatype that would
> be able to contain such large values).
>
> Note that there's also still a corner case that this doesn't handle. The
> DT specification states, if I remember correctly, that #address-cells
> and #size-cells are inherited. That means with the current code we will
> wrongly parse something like this:
>
> / {
> ...
> #address-cells = <1>;
> #size-cells = <1>;
> ...
> bus at XXXXXXXX {
> ...
> device at XXXXXXXX {
> ...
> reg = <0xXXXXXXXX 0x1000>;
> ...
> };
> ...
> };
> ...
> };
>
> According to the DT specification the bus at XXXXXXXX node would inherit
> #address-cells = <1> and #size-cells = <1> from the root node. However
> with libfdt what really happens is that since bus at XXXXXXXX does not have
> either property it will default to 2 in both cases. I'm not sure if this
> really is a problem. Typically nodes are not nested that deeply, or if
> they are then, typically, they explicitly contain #address-cells and
> #size-cells properties.
I don't think #address-cells/#size-cells do actually get inherited.
Admittedly some other properties (e.g. interrupt-parent) do, but
according to:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2008-January/049113.html
[PATCH] powerpc: #address-cells & #size-cells properties not inherited
... and my vague memory, these two don't.
You can search Google for e.g. "#address-cells inherited" and find a
number of similar assertions.
^ permalink raw reply [flat|nested] 6+ messages in thread* [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit
2015-08-04 15:23 ` Stephen Warren
@ 2015-08-04 15:36 ` Thierry Reding
0 siblings, 0 replies; 6+ messages in thread
From: Thierry Reding @ 2015-08-04 15:36 UTC (permalink / raw)
To: u-boot
On Tue, Aug 04, 2015 at 09:23:27AM -0600, Stephen Warren wrote:
> On 08/04/2015 08:26 AM, Thierry Reding wrote:
> ... [ discussion of new fdtdec_get_addr_size() implementation]
> >So what this does is really fix parsing of address and size cells in the
> >general case, though it would still fail for values of #address-cells or
> >#size-cells bigger than 2 (because we don't have a datatype that would
> >be able to contain such large values).
> >
> >Note that there's also still a corner case that this doesn't handle. The
> >DT specification states, if I remember correctly, that #address-cells
> >and #size-cells are inherited. That means with the current code we will
> >wrongly parse something like this:
> >
> > / {
> > ...
> > #address-cells = <1>;
> > #size-cells = <1>;
> > ...
> > bus at XXXXXXXX {
> > ...
> > device at XXXXXXXX {
> > ...
> > reg = <0xXXXXXXXX 0x1000>;
> > ...
> > };
> > ...
> > };
> > ...
> > };
> >
> >According to the DT specification the bus at XXXXXXXX node would inherit
> >#address-cells = <1> and #size-cells = <1> from the root node. However
> >with libfdt what really happens is that since bus at XXXXXXXX does not have
> >either property it will default to 2 in both cases. I'm not sure if this
> >really is a problem. Typically nodes are not nested that deeply, or if
> >they are then, typically, they explicitly contain #address-cells and
> >#size-cells properties.
>
> I don't think #address-cells/#size-cells do actually get inherited.
> Admittedly some other properties (e.g. interrupt-parent) do, but according
> to:
>
> https://lists.ozlabs.org/pipermail/linuxppc-dev/2008-January/049113.html
> [PATCH] powerpc: #address-cells & #size-cells properties not inherited
>
> ... and my vague memory, these two don't.
>
> You can search Google for e.g. "#address-cells inherited" and find a number
> of similar assertions.
Okay, that's good. It means there's not even a corner case. =)
Thierry
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Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-07-23 16:51 [U-Boot] [PATCH] fdt: Fix fdtdec_get_addr_size() for 64-bit Stephen Warren
2015-07-27 17:13 ` Simon Glass
2015-08-02 21:27 ` Simon Glass
2015-08-04 14:26 ` Thierry Reding
2015-08-04 15:23 ` Stephen Warren
2015-08-04 15:36 ` Thierry Reding
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