[meta-freescale] iMX6 - CPU frequency lowered during LDO bypass setting

ansaris ansaris at iwavesystems.com
Fri Apr 17 06:03:17 PDT 2015


Hi,

We are using imx6Q sabresd platform for our development with Linux 
3.14.28_1.0.0-GA BSP but initially we used Linux 3.10.17_1.0.0-GA BSP.

We have gone through below files from Linux 3.14.28_1.0.0-GA(File-1) and 
Linux 3.10.17_1.0.0-GA (FIle-2) BSPs.
File-1: ~/u-boot-imx/board/freescale/mx6sabresd/mx6sabresd.c
File-2: ~/u-boot-imx/board/freescale/mx6qsabresd/mx6qsabresd.c

We could see some changes are added in File-1(compare to File-2).

In below function, we understood that the CPU frequency is lowered to 
400Mhz before doing the LDO bypass and CPU frequency is increased to 
800Mhz after the LDO bypass settings.
"ldo_mode_set"
In FIle-2 (Linux 3.10.17_1.0.0-GA), the below function will do the LDO 
bypass settings without changing the CPU frequency.
"ldo_mode_set"

We would like to know, during the LDO bypass settings why the CPU 
frequency is lowered in File-1(Linux 3.14.28_1.0.0-GA)?  Is it 
recommended  to do the same.?

Thank You,
Regards,
Ansari



More information about the meta-freescale mailing list