[PATCH 2/7] ARM: dts: skeleton: add unit name to memory node

Vladimir Zapolskiy vladimir_zapolskiy at mentor.com
Wed Mar 30 06:06:56 PDT 2016


On 30.03.2016 14:06, Mark Rutland wrote:
> On Wed, Mar 30, 2016 at 12:30:41AM +0200, Joachim Eastwood wrote:
>> Add unit name to memory to remove the following warning:
>>  Warning (unit_address_vs_reg): Node /memory has a reg or ranges
>> 				property, but no unit name
> 
> If anything, it would be better to get rid of the memory node from the
> skeleton DTs.
> 
> For DTs which have a memory node there's no problem, and DTs which
> expect a bootlaoder to fill things in have a logical place to document
> that fact.

Generally I support this.

U-boot still creates or fixes up "/memory" node only, assuming that
a bootloader is updated rarely the kernel should continue to process
in expected way "/memory" device node, also note that ePAPR says

ePAPR> If a system has multiple ranges of memory, multiple memory nodes
ePAPR> can be created, or the ranges can be specified in the reg property
ePAPR> of a single memory node.

Having just a DT on hand it won't be possible to make assumptions about
a bootloader, also "/memory" without a given unit address is used by
other kernels and a bootloader can respect this.

The only problem I see if DTB is updated on a board but a board bootloader
on fix-up is capable to fill a preexisting "/memory" device node in only,
otherwise it is not clear why the device node is present in skeleton.dtsi.

>> Signed-off-by: Joachim Eastwood <manabian at gmail.com>
>> ---
>>  arch/arm/boot/dts/skeleton.dtsi   | 2 +-
>>  arch/arm/boot/dts/skeleton64.dtsi | 2 +-
>>  2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/skeleton.dtsi b/arch/arm/boot/dts/skeleton.dtsi
>> index b41d241..a20da0a 100644
>> --- a/arch/arm/boot/dts/skeleton.dtsi
>> +++ b/arch/arm/boot/dts/skeleton.dtsi
>> @@ -9,5 +9,5 @@
>>  	#size-cells = <1>;
>>  	chosen { };
>>  	aliases { };
>> -	memory { device_type = "memory"; reg = <0 0>; };
>> +	memory at 0 { device_type = "memory"; reg = <0 0>; };
>>  };
>> diff --git a/arch/arm/boot/dts/skeleton64.dtsi b/arch/arm/boot/dts/skeleton64.dtsi
>> index b5d7f36..6dbe9f9 100644
>> --- a/arch/arm/boot/dts/skeleton64.dtsi
>> +++ b/arch/arm/boot/dts/skeleton64.dtsi
>> @@ -9,5 +9,5 @@
>>  	#size-cells = <2>;
>>  	chosen { };
>>  	aliases { };
>> -	memory { device_type = "memory"; reg = <0 0 0 0>; };
>> +	memory at 0 { device_type = "memory"; reg = <0 0 0 0>; };
>>  };
>> -- 
>> 2.7.4
>>

--
With best wishes,
Vladimir



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