The reason i.MX6DQ VDD_ARM_CAP setting was changed by L3.10.53_1.1.0-ga.

[satoshishimoda]

Hi community,

I have a question about i.MX6DQ Linux BSP.

Please see arch/arm/boot/dts/imx6q.dtsi in L3.10.17_1.0.0-ga.

The VDD_ARM_CAP voltage when 792MHz is set to 1.150V in line 33.

Next, please see same file in L3.10.53_1.1.0-ga, it is set  to 1.175V in line 33.

Would you let me know why the setting was changed?

To add some margine from i.MX6DQ VDD_ARM_CAP min value (1.1.50V @ up to 792MHz)?

Best Regards,

Satoshi Shimoda

[Yuri · Accepted solution]

Hi,

   Some customers report about system instability when using the LDO bypass

mode. After careful investigations voltage ranges in LDO bypass mode have been

slightly modified to get more reliable working environment.

Have a great day,
Yuri

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[satoshishimoda]

Dear Yuri,

Thank you for your reply, and sorry for delay.

OK, I understood why the voltage setting was raised.

By the way, the voltage by LTIB (L3.0.35_4.1.0) is same as L3.10.53_1.1.0-ga.

So the voltage was set lower in L3.10.17 than L3.0.35, and returned to the original value by L3.10.53.

Would you let me know why L3.10.17 set lower VDD_ARM_CAP voltage than L3.0.35 at all?

For lower power consumption?

Best Regards,

Satoshi Shimoda