ARM: dts: sunxi: Fix cpufreq instabilities

PATCH Superseded Chen-Yu Tsai 2 participants 6 messages Mar 20, 2015 – Mar 24, 2015

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Device tree bindings Arm/Allwinner sunXi SoC support

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Chen-Yu Tsai

author

2015-03-20 06:49 UTC #0 lore raw

v2 cover ARM: dts: sunxi: Fix cpufreq instabilities

Hi Maxime,

Here's v2 of the sunxi cpufreq dts fixes, aimed at 4.0.

The first patch limits the Olimex A10-Lime to 912MHz, as a few people reported on IRC that it was unstable at 1008MHz.

The second patch removes the overclocking settings from sun[457]i dts, so all the boards will be stable, regardless of whether regulators were added or not.

I would like to revisit this after the new OPP bindings are merged and support added to cpufreq-dt.

Changes since v1:

- Added sun4i dts fixes
- Corrected A10-Lime settings to match sun4i

Regards
ChenYu

Chen-Yu Tsai (2):
ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
ARM: dts: sunxi: Remove overclocked/overvoltaged OPP

 arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 11 +++++++++++
 arch/arm/boot/dts/sun4i-a10.dtsi               |  3 +--
 arch/arm/boot/dts/sun5i-a13.dtsi               |  3 +--
 arch/arm/boot/dts/sun7i-a20.dtsi               |  3 +--
 4 files changed, 14 insertions(+), 6 deletions(-)

Signature · 1 line

2.1.4

Chen-Yu Tsai

author

2015-03-20 06:49 UTC #1 lore raw

PATCH v2 1/2 ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting

The Olimex A10-Lime is known to be unstable when running at 1008MHz.

Signed-off-by Chen-Yu Tsai <[email protected]>

---
 arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 11 +++++++++++
 1 file changed, 11 insertions(+)

arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts +11 -0

index 31dc2f1c3870..df9535b5009c 100644
@@ -74,6 +74,17 @@
 	status = "okay";
 };
 
+&cpu0 {
+	/* The A10-Lime is known to be unstable when running at 1008 MHz */
+	operating-points = <
+		/* kHz    uV */
+		912000  1350000
+		864000  1300000
+		624000  1250000
+		>;
+	cooling-max-level = <2>;
+};
+
 &ehci0 {
 	status = "okay";
 };

Signature · 1 line

2.1.4

Chen-Yu Tsai

author

2015-03-20 06:49 UTC #2 lore raw

PATCH v2 2/2 ARM: dts: sunxi: Remove overclocked/overvoltaged OPP

In reply to Chen-Yu Tsai

Without proper regulator support for individual boards, it is dangerous to have overclocked/overvoltaged OPPs in the list. Cpufreq will increase the frequency without the accompanying voltage increase, resulting in an unstable system.

Remove them for now. We can revisit them with the new version of OPP bindings, which support boost settings and frequency ranges, among other things.

Signed-off-by Chen-Yu Tsai <[email protected]>

---
 arch/arm/boot/dts/sun4i-a10.dtsi | 3 +--
 arch/arm/boot/dts/sun5i-a13.dtsi | 3 +--
 arch/arm/boot/dts/sun7i-a20.dtsi | 3 +--
 3 files changed, 3 insertions(+), 6 deletions(-)

arch/arm/boot/dts/sun4i-a10.dtsi +1 -2

index c66352bb977c..17e4598db176 100644
@@ -111,7 +111,6 @@
 			clock-latency = <244144>; /* 8 32k periods */
 			operating-points = <
 				/* kHz    uV */
-				1056000 1500000
 				1008000 1400000
 				912000  1350000
 				864000  1300000

@@ -119,7 +118,7 @@
 				>;
 			#cooling-cells = <2>;
 			cooling-min-level = <0>;
-			cooling-max-level = <4>;
+			cooling-max-level = <3>;
 		};
 	};

arch/arm/boot/dts/sun5i-a13.dtsi +1 -2

index 5d9ce84486bb..39264f7c7ae6 100644
@@ -140,7 +140,6 @@
 	clock-latency = <244144>; /* 8 32k periods */
 	operating-points = <
 		/* kHz    uV */
-		1104000	1500000
 		1008000 1400000
 		912000  1350000
 		864000  1300000

@@ -150,7 +149,7 @@
 		>;
 	#cooling-cells = <2>;
 	cooling-min-level = <0>;
-	cooling-max-level = <6>;
+	cooling-max-level = <5>;
 };
 
 &ehci0 {

arch/arm/boot/dts/sun7i-a20.dtsi +1 -2

index 3a8530b79f1c..fdd181792b4b 100644
@@ -105,7 +105,6 @@
 			clock-latency = <244144>; /* 8 32k periods */
 			operating-points = <
 				/* kHz    uV */
-				1008000 1450000
 				960000  1400000
 				912000  1400000
 				864000  1300000

@@ -116,7 +115,7 @@
 				>;
 			#cooling-cells = <2>;
 			cooling-min-level = <0>;
-			cooling-max-level = <7>;
+			cooling-max-level = <6>;
 		};
 
 		cpu at 1 {

Signature · 1 line

2.1.4

Maxime Ripard

Applied

2015-03-21 18:20 UTC #3 lore raw

v2 cover ARM: dts: sunxi: Fix cpufreq instabilities

In reply to Chen-Yu Tsai

Quoted 7 lines · Chen-Yu Tsai

Hi Maxime,
Here's v2 of the sunxi cpufreq dts fixes, aimed at 4.0.
The first patch limits the Olimex A10-Lime to 912MHz, as a few people reported on IRC that it was unstable at 1008MHz.

Quoted 6 lines

The second patch removes the overclocking settings from sun[457]i dts, so all the boards will be stable, regardless of whether regulators were added or not.
I would like to revisit this after the new OPP bindings are merged and support added to cpufreq-dt.

Applied both, thanks!

Maxime

Signature · 10 lines

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

author

2015-03-23 23:43 UTC #4 lore raw

v2 cover ARM: dts: sunxi: Fix cpufreq instabilities

Quoted 8 lines · Maxime Ripard

Quoted 7 lines · Chen-Yu Tsai
Hi Maxime,
Here's v2 of the sunxi cpufreq dts fixes, aimed at 4.0.
The first patch limits the Olimex A10-Lime to 912MHz, as a few people reported on IRC that it was unstable at 1008MHz.

Quoted 8 lines

Quoted 6 lines
The second patch removes the overclocking settings from sun[457]i dts, so all the boards will be stable, regardless of whether regulators were added or not.
I would like to revisit this after the new OPP bindings are merged and support added to cpufreq-dt.
Applied both, thanks!

I see you applied them under sunxi/dt-for-4.1.
Shouldn't we merge them for 4.0 fixes?

ChenYu

Maxime Ripard

2015-03-24 00:07 UTC #5 lore raw

v2 cover ARM: dts: sunxi: Fix cpufreq instabilities

Quoted 14 lines · Chen-Yu Tsai

Quoted 12 lines · Maxime Ripard
Quoted 11 lines · Chen-Yu Tsai
Hi Maxime,
Here's v2 of the sunxi cpufreq dts fixes, aimed at 4.0.
The first patch limits the Olimex A10-Lime to 912MHz, as a few people reported on IRC that it was unstable at 1008MHz.
The second patch removes the overclocking settings from sun[457]i dts, so all the boards will be stable, regardless of whether regulators were added or not.

Quoted 7 lines

Quoted 4 lines
Quoted 2 lines
I would like to revisit this after the new OPP bindings are merged and support added to cpufreq-dt.
Applied both, thanks!
I see you applied them under sunxi/dt-for-4.1.
Shouldn't we merge them for 4.0 fixes?

Your patch doesn't apply on 4.0 unfortunately.

I dropped it at the moment, would you care to resend it?

Thanks,
Maxime

Signature · 10 lines

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