Re: [PATCH v2 1/2] arm64: dts: qcom: msm8953: Set initial address for memory

[Luca Weiss <luca@z3ntu.xyz>]

On Sonntag, 3. Dezember 2023 05:20:23 CET Bjorn Andersson wrote:
> On Sat, Nov 25, 2023 at 01:19:27PM +0100, Luca Weiss wrote:
> > The dtbs_check really doesn't like having memory without reg set.
> > 
> > The base address depends on the amount of RAM you have:
> >   <= 2.00 GiB RAM: 0x80000000
> >   
> >    = 3.00 GiB RAM: 0x40000000
> >    = 3.75 GiB RAM: 0x10000000
> >  
> >  (more does not fit into the 32-bit physical address space)
> > 
> > So, let's pick one of the values, 0x10000000 which is used on devices
> > with 3.75 GiB RAM. Since the bootloader will update it to what's present
> > on the device it doesn't matter too much.
> > 
> > Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
> > ---
> > 
> >  arch/arm64/boot/dts/qcom/msm8953.dtsi | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/arm64/boot/dts/qcom/msm8953.dtsi
> > b/arch/arm64/boot/dts/qcom/msm8953.dtsi index e7de7632669a..a3ba24ca599b
> > 100644
> > --- a/arch/arm64/boot/dts/qcom/msm8953.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/msm8953.dtsi
> > @@ -174,10 +174,10 @@ scm: scm {
> > 
> >  		};
> >  	
> >  	};
> > 
> > -	memory {
> 
> Wouldn't it be sufficient to add @0 here, to please dtbs_check?

The checker itself also seems to be okay with memory@0 and no other change,
but there's this warning with W=1

arch/arm64/boot/dts/qcom/msm8953.dtsi:177.11-181.4: Warning (unique_unit_address_if_enabled): /memory@0: duplicate unit-address (also used in node /soc@0)

So probably we should still try to put it at a reasonable address like
0x10000000?

Regards
Luca

> 
> Regards,
> Bjorn
> 
> > +	memory@10000000 {
> > 
> >  		device_type = "memory";
> >  		/* We expect the bootloader to fill in the reg */
> > 
> > -		reg = <0 0 0 0>;
> > +		reg = <0 0x10000000 0 0>;
> > 
> >  	};
> >  	
> >  	pmu {