Re: [PATCH 5/8] omap_hsmmc: RX51: set padconfs to pull down when powering off eMMC

Adrian Hunter
2010-01-14T07:57:45Z

Nishanth Menon wrote:
> Tony Lindgren had written, on 01/13/2010 03:00 PM, the following:
>> * Tony Lindgren <tony@atomide.com> [100113 12:38]:
>>> * Tony Lindgren <tony@atomide.com> [100113 12:36]:
>>>> You might want to check what happens in omap off-idle mode in these cases
>>>> and see if enabling OMAP_PIN_OFF_INPUT_PULLDOWN makes any difference in
>>>> power consumption in off state. That probably does not matter unless the
>>>> floating lines cause the eMMC to do something on it's own :)
>>> Or OMAP_PIN_OFF_OUTPUT_LOW actually.
>> One more time.. Most likely OMAP_PIN_OFF_INPUT_PULLDOWN is safer
>> in general as the OMAP_PIN_OFF_OUTPUT_LOW does not work for all
>> pins. According to the TRM, OMAP_PIN_OFF_OUTPUT_LOW only works
>> for pins where at least one of the mux modes supports output
>> mode.
>
> is'nt vaux/vmmc/whatever voltage to eMMC shutoff for the device on the
> board in off mode? I wonder why the behavior is seen. The only thing
> that I am worried is that the board potentially will draw more current
> as the lines are driven low.

OMAP is not OFF just the eMMC. Current is sucked out of the data lines
through the eMMC to the regulator which is off.