[PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications

[PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications

[Timo Sigurdsson]

sun7i-a20.dtsi contains a cpufreq operating point at 0.9 volts. The minimum
CPU voltage for the Allwinner A20 SoC, however, is 1.0 volts. Thus, raise
the voltage for the lowest operating point to 1.0 volts in order to stay
within the SoC specifications. It is an undervolted setting that isn't
stable across all SoCs and boards out there.

Signed-off-by: Timo Sigurdsson <public_timo.s-fWgRPtSzPNU3WX+qO2AYSQ@public.gmane.org>
---
Changes since v1:

- Fixed checkpatch warnings
- Changed the commit message and title to clarify that this is not a board-specific issue, but rather a limitation by the SoC  
---
 arch/arm/boot/dts/sun7i-a20.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index 6a63f30..f5f384c 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -107,7 +107,7 @@
 				720000	1200000
 				528000	1100000
 				312000	1000000
-				144000	900000
+				144000	1000000
 				>;
 			#cooling-cells = <2>;
 			cooling-min-level = <0>;
-- 
2.1.4

Re: [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications

[Iain Paton]

Acked-by: Iain Paton <ipaton0-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

On 04/08/15 22:08, Timo Sigurdsson wrote:
> sun7i-a20.dtsi contains a cpufreq operating point at 0.9 volts. The minimum
> CPU voltage for the Allwinner A20 SoC, however, is 1.0 volts. Thus, raise
> the voltage for the lowest operating point to 1.0 volts in order to stay
> within the SoC specifications. It is an undervolted setting that isn't
> stable across all SoCs and boards out there.
> 
> Signed-off-by: Timo Sigurdsson <public_timo.s-fWgRPtSzPNU3WX+qO2AYSQ@public.gmane.org>
> ---
> Changes since v1:
> 
> - Fixed checkpatch warnings
> - Changed the commit message and title to clarify that this is not a board-specific issue, but rather a limitation by the SoC  
> ---
>  arch/arm/boot/dts/sun7i-a20.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
> index 6a63f30..f5f384c 100644
> --- a/arch/arm/boot/dts/sun7i-a20.dtsi
> +++ b/arch/arm/boot/dts/sun7i-a20.dtsi
> @@ -107,7 +107,7 @@
>  				720000	1200000
>  				528000	1100000
>  				312000	1000000
> -				144000	900000
> +				144000	1000000
>  				>;
>  			#cooling-cells = <2>;
>  			cooling-min-level = <0>;
> 

Re: [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 672 bytes --]

Hi Timo,

On Tue, Aug 04, 2015 at 11:08:01PM +0200, Timo Sigurdsson wrote:
> sun7i-a20.dtsi contains a cpufreq operating point at 0.9 volts. The minimum
> CPU voltage for the Allwinner A20 SoC, however, is 1.0 volts. Thus, raise
> the voltage for the lowest operating point to 1.0 volts in order to stay
> within the SoC specifications. It is an undervolted setting that isn't
> stable across all SoCs and boards out there.
> 
> Signed-off-by: Timo Sigurdsson <public_timo.s-fWgRPtSzPNU3WX+qO2AYSQ@public.gmane.org>

Added Iain's Ack, and Cc stable

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com