maemo.org - Talk - View Single Post - Battery consumption analysis

	juise-	2010-02-25 , 12:24
	Posts: 186 \| Thanked: 192 times \| Joined on Jan 2010 @ Finland	#135

Originally Posted by slender

SO. Even I did not see anything running with high cpu in top my device was still using battery at very high rate at idle (previous post). From powertop entry we can see that something is keeping processor in C2 state and waking up it constanlty and depleting my battery.

This is similar to what I have observed sometimes. I also think that I've seen the device to come out of this without rebooting, but my memory may fail.

Edit:
For me, this has already been happening in PR1.1, so it's probably not new to 1.1.1.

Originally Posted by slender

Before reboot:

Code:

IRQ#    | Activity   | Type           | Name
--------+------------+----------------+-----------
     12 |       3086 |           INTC | DMA

After reboot:

Code:

IRQ#    | Activity   | Type           | Name
--------+------------+----------------+-----------
     12 |        156 |           INTC | DMA

It seems that there's some DMA activity going on, which probably shouldn't be happening if the device is idle and no apps are running. I'm not familiar with the OMAP hardware specifics, but this high interrupt rate definitely can prevent the CPU from sleeping.

I think you have a good set of data here, you should consider filing a bug (if this same issue isn't already posted).

Last edited by juise-; 2010-02-25 at 12:28.

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