Re: [PATCHv5 2/5] ARM: dts: Odroid-XU3 Enable TMU at Exynos5422 base

Krzysztof Kozlowski
2015-05-24T04:33:39Z

2015-05-24 2:35 GMT+09:00 Anand Moon <linux.amoon@gmail.com>:
> Hi Krzysztof,
>
> I did some debugging on the this using powerdebug utility.
> Using LDO7 to control TMU seams to me correct option compared to BUCK3.
>
> Setting LDO7 to control TMU I observed following output on powerdebug.
> I observed that the power drawn by the board on Odroid show is much
> less compare to BUCK3 on the same setup.
> I can see the HDMI output on Odroid-V2 display screen.
> I have done some stress testing on this configuration and It worked correctly.
>
> Powerdebug output using LDO7
> ---------------------------------------------------------------------------------------------------------------
> PowerDebug 0.7.3 Clocks Regulators Sensors Gpio
> Name Status State Type Users Microvolts
> Min u-volts Max u-volts
> phy 0 0
> 0 0
> phy 0 0
> 0 0
> vdd_ldo1 enabled voltage 0 1000000
> 1000000 1000000
> LDO1 0 0
> 0 0
> LDO2 enabled voltage 0 1800000
> 0 0
> vdd_ldo3 enabled voltage 0 1800000
> 1800000 1800000
> LDO3 0 0
> 0 0
> LDO4 enabled voltage 0 1800000
> 0 0
> vdd_ldo5 enabled voltage 0 1800000
> 1800000 1800000
> LDO5 0 0
> 0 0
> vdd_ldo6 enabled voltage 0 1000000
> 1000000 1000000
> hdmi okay 0 0
> 0 0
> hdmi okay 0 0
> 0 0
> LDO6 0 0
> 0 0
> vdd_ldo7 enabled voltage 0 1800000
> 1800000 1800000
> hdmi okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> LDO7 0 0
> 0 0
> vdd_ldo8 enabled voltage 0 1800000
> 1800000 1800000
> LDO8 0 0
> 0 0
> vdd_ldo9 enabled voltage 0 3000000
> 3000000 3000000
> LDO9 0 0
> 0 0
>
> Powerdebug output using BUCK3.
> --------------------------------------------------------------------------------------------------------------------------
> PowerDebug 0.7.3 Clocks Regulators Sensors Gpio
> Name Status State Type Users Microvolts
> Min u-volts Max u-volts
> LDO21 disabled voltage 0 1800000
> 0 0
> LDO22 disabled voltage 0 1200000
> 0 0
> LDO23 enabled voltage 0 1100000
> 0 0
> tsp_io enabled voltage 0 2800000
> 2800000 2800000
> LDO24 0 0
> 0 0
> LDO25 disabled voltage 0 1800000
> 0 0
> vdd_ldo26 enabled voltage 0 3000000
> 3000000 3000000
> LDO26 0 0
> 0 0
> LDO27 enabled voltage 0 1000000
> 0 0
> LDO28 disabled voltage 0 3300000
> 0 0
> LDO29 disabled voltage 0 1800000
> 0 0
> LDO30 disabled voltage 0 1800000
> 0 0
> LDO31 disabled voltage 0 1800000
> 0 0
> LDO32 disabled voltage 0 1800000
> 0 0
> LDO33 disabled voltage 0 1800000
> 0 0
> LDO34 disabled voltage 0 3000000
> 0 0
> LDO35 disabled voltage 0 1600000
> 0 0
> LDO36 disabled voltage 0 1800000
> 0 0
> LDO37 disabled voltage 0 1800000
> 0 0
> LDO38 disabled voltage 0 2800000
> 0 0
> vdd_mif enabled voltage 0 1100000
> 800000 1300000
> BUCK1 0 0
> 0 0
> vdd_arm enabled voltage 0 1000000
> 800000 1500000
> BUCK2 0 0
> 0 0
> vdd_int enabled voltage 0 1000000
> 800000 1400000
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> tmu okay 0 0
> 0 0
> BUCK3 0 0
> 0 0
> vdd_g3d enabled voltage 0 1000000
> 800000 1400000
> BUCK4 0 0
> 0 0
> vdd_mem enabled voltage 0 1200000
> 800000 1400000
> BUCK5 0 0
> 0 0
> vdd_kfc enabled voltage 0 1025000
> 800000 1500000
>
> So I would like to go with LDO7.
>
> Please share your thoughts.

I don't understand how grepping through /sys/class/regulator helps in
making this decision. I just don't get it. Can you please explain it
to me?

Best regards,
Krzysztof