linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications
@ 2015-08-04 21:08 Timo Sigurdsson
  2015-08-09 22:58 ` [linux-sunxi] " Iain Paton
  2015-08-17 15:18 ` Maxime Ripard
  0 siblings, 2 replies; 3+ messages in thread
From: Timo Sigurdsson @ 2015-08-04 21:08 UTC (permalink / raw)
  To: linux-arm-kernel

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@silentcreek.de>
---
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

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* [linux-sunxi] [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications
  2015-08-04 21:08 [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications Timo Sigurdsson
@ 2015-08-09 22:58 ` Iain Paton
  2015-08-17 15:18 ` Maxime Ripard
  1 sibling, 0 replies; 3+ messages in thread
From: Iain Paton @ 2015-08-09 22:58 UTC (permalink / raw)
  To: linux-arm-kernel

Acked-by: Iain Paton <ipaton0@gmail.com>

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@silentcreek.de>
> ---
> 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>;
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications
  2015-08-04 21:08 [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications Timo Sigurdsson
  2015-08-09 22:58 ` [linux-sunxi] " Iain Paton
@ 2015-08-17 15:18 ` Maxime Ripard
  1 sibling, 0 replies; 3+ messages in thread
From: Maxime Ripard @ 2015-08-17 15:18 UTC (permalink / raw)
  To: linux-arm-kernel

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@silentcreek.de>

Added Iain's Ack, and Cc stable

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20150817/fb0da564/attachment.sig>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2015-08-17 15:18 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-08-04 21:08 [PATCH v2] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications Timo Sigurdsson
2015-08-09 22:58 ` [linux-sunxi] " Iain Paton
2015-08-17 15:18 ` Maxime Ripard

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).