Re: [PATCH] mmc: append a file to change host clock at run time

[Andy Shevchenko]

On Tue, Oct 12, 2010 at 6:17 PM, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> For debugging power managment features there is quite convenient to have a
> possibility to change MMC host controller clock at run time. This patch adds
> 'clock' file under MMC host root of debugfs.
>
> Usage as follows:
>
> Â Â Â Â# cat /sys/kernel/debug/mmc0/clock
> Â Â Â Â24000000
Actually this value should be 52000000 here.

>
> Â Â Â Â# echo "1000000000" > /sys/kernel/debug/mmc0/clock
> Â Â Â Â# cat /sys/kernel/debug/mmc0/clock
> Â Â Â Â52000000
>
> Â Â Â Â# echo "48000000" > /sys/kernel/debug/mmc0/clock
> Â Â Â Â# cat /sys/kernel/debug/mmc0/clock
> Â Â Â Â48000000
>
> The second piece of example shows limits which are applied accordingly to used
> host driver.


-- 
With Best Regards,
Andy Shevchenko
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