[U-Boot] [PATCH 3/3] mx6sl: Add initial support for mx6slevk board

Fabio Estevam festevam at gmail.com
Sat Apr 6 16:15:19 CEST 2013


On Sat, Apr 6, 2013 at 10:52 AM, Dirk Behme <dirk.behme at gmail.com> wrote:

> Most probably it would be sufficient to enable only the clocks needed for
> booting ;) And not all clocks. On the other boards we do
>
> /* set the default clock gate to save power */
> DATA 4 0x020c4068 0x00C03F3F
> DATA 4 0x020c406c 0x0030FC03
> DATA 4 0x020c4070 0x0FFFC000
> DATA 4 0x020c4074 0x3FF00000
> DATA 4 0x020c4078 0x00FFF300
> DATA 4 0x020c407c 0x0F0000C3
> DATA 4 0x020c4080 0x000003FF
>
> http://git.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=blob;f=board/freescale/imx/ddr/mx6q_4x_mt41j128.cfg;h=f4cae5eeb9899ab4ba937ae286e004d6861f1d43;hb=refs/heads/master#l161
>
> Do you like to try anything similar here, too?

No, sorry. It is possible to turn some clocks off, for sure,  but I do
not see real benefit by doing this on this solo-lite board.

U-boot runs only for few seconds (or ms), so not much of power savings
we can do in the bootloader.

I am just setting the clocks to the default states, so it is up to the
kernel to manage the clocks as needed.

And I don't want to face the risk to turn some clocks off and then
realize later that the kernel was expecting a clock to be on and start
seeing weird run-time issues.


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