[PATCH v2 1/2] ARM: dts: imx6q-cm-fx6: fix the operation points

[PATCH v2 1/2] ARM: dts: imx6q-cm-fx6: fix the operation points

[christopher.spinrath-vA1bhqPz9FBZXbeN9DUtxg]

From: Valentin Raevsky <valentin-UTxiZqZC01RS1MOuV/RT9w@public.gmane.org>

The current ldo settings of the cm-fx6 do not allow 1.2GHz cpu
frequency. At this frequency the module behaves unstable.

But the imx6q fuse indicates that 1.2GHz operation is possible.
Hence, remove the 1.2GHz operation point in the device tree.

Signed-off-by: Valentin Raevsky <valentin-UTxiZqZC01RS1MOuV/RT9w@public.gmane.org>
[christopher.spinrath-vA1bhqPz9FBZXbeN9DUtxg@public.gmane.org: enhanced commit message and adjust
 remaining operation points to match the ones in imx6q.dtsi]
Signed-off-by: Christopher Spinrath <christopher.spinrath-vA1bhqPz9FBZXbeN9DUtxg@public.gmane.org>
---

Notes:
    Changes since v1:
     - Enhance commit message to explain that we cannot rely on the imx6q
       fuse to restrict the frequency
     - put the same information into a comment in the device tree
     - fix the remaining operation points to match the ones given in
       imx6q.dtsi

 arch/arm/boot/dts/imx6q-cm-fx6.dts | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/arch/arm/boot/dts/imx6q-cm-fx6.dts b/arch/arm/boot/dts/imx6q-cm-fx6.dts
index 6d8d5e9..0038f0e 100644
--- a/arch/arm/boot/dts/imx6q-cm-fx6.dts
+++ b/arch/arm/boot/dts/imx6q-cm-fx6.dts
@@ -91,6 +91,27 @@
 	};
 };
 
+&cpu0 {
+	/* Although the imx6q fuse indicates that 1.2GHz operation is possible,
+	 * the module behaves unstable at this frequency. Hence, remove the
+	 * 1.2GHz operation point here.
+	 */
+	operating-points = <
+		/* kHz	uV */
+		996000	1250000
+		852000	1250000
+		792000	1175000
+		396000	975000
+	>;
+	fsl,soc-operating-points = <
+		/* ARM kHz	SOC-PU uV */
+		996000		1250000
+		852000		1250000
+		792000		1175000
+		396000		1175000
+	>;
+};
+
 &ecspi1 {
 	fsl,spi-num-chipselects = <2>;
 	cs-gpios = <&gpio2 30 GPIO_ACTIVE_HIGH>, <&gpio3 19 GPIO_ACTIVE_HIGH>;
-- 
2.8.3

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Re: [PATCH v2 1/2] ARM: dts: imx6q-cm-fx6: fix the operation points

[Fabio Estevam]

On Sun, Jun 12, 2016 at 12:19 PM,  <christopher.spinrath-vA1bhqPz9FBZXbeN9DUtxg@public.gmane.org> wrote:

> +&cpu0 {
> +       /* Although the imx6q fuse indicates that 1.2GHz operation is possible,
> +        * the module behaves unstable at this frequency. Hence, remove the
> +        * 1.2GHz operation point here.
> +        */

Just one minor comment.

>From Documentation/CodingStyle:

"The preferred style for long (multi-line) comments is:

    /*
     * This is the preferred style for multi-line
     * comments in the Linux kernel source code.
     * Please use it consistently.
     *
     * Description:  A column of asterisks on the left side,
     * with beginning and ending almost-blank lines.
     */
"

Reviewed-by: Fabio Estevam <fabio.estevam-3arQi8VN3Tc@public.gmane.org>
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Re: [PATCH v2 1/2] ARM: dts: imx6q-cm-fx6: fix the operation points

[Christopher Spinrath]

Hi Fabio,

thanks again for your review!

On 06/13/2016 12:49 AM, Fabio Estevam wrote:
> On Sun, Jun 12, 2016 at 12:19 PM,  <christopher.spinrath-vA1bhqPz9FBZXbeN9DUtxg@public.gmane.org> wrote:
> 
>> +&cpu0 {
>> +       /* Although the imx6q fuse indicates that 1.2GHz operation is possible,
>> +        * the module behaves unstable at this frequency. Hence, remove the
>> +        * 1.2GHz operation point here.
>> +        */
> 
> Just one minor comment.
> 
> From Documentation/CodingStyle:
> 
> "The preferred style for long (multi-line) comments is:
> 
>     /*
>      * This is the preferred style for multi-line
>      * comments in the Linux kernel source code.
>      * Please use it consistently.
>      *
>      * Description:  A column of asterisks on the left side,
>      * with beginning and ending almost-blank lines.
>      */
> "
> 
ups, I took only a quick look and picked the comment style for net/ ...
I will fix it and read more carefully next time.

Thanks,
Christopher

> Reviewed-by: Fabio Estevam <fabio.estevam-3arQi8VN3Tc@public.gmane.org>
> 
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