* Paul Walmsley paul@pwsan.com [140725 12:16]:
On Mon, 7 Jul 2014, Tony Lindgren wrote:
With v3.16-rc4 the PM features for omap3 should be working finally for device tree based booting. At lest beaglexm and 3xxevm should work.
Just to follow up briefly on this: there was indeed a bug in the OMAP3 test scripts here that resulted in the UART wakeup not being enabled.
Once that was fixed, system suspend-based chip-retention and chip-off modes work.
OK
However, scheduler-idle based chip-retention and chip-off still are not working. Looking at the logs, it appears that some domains are not dynamically going idle. For example, looking at:
http://www.pwsan.com/omap/testlogs/test_v3.16-rc6/20140724142225/pm/37xxevm/...
it can be seen that core_pwrdm's retention count doesn't increase between the two PM debug dumps. The important lines are:
core_pwrdm (ON),OFF:0,RET:2,INA:0,ON:3,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
and
core_pwrdm (ON),OFF:0,RET:2,INA:0,ON:3,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
That's why the test reports mark the dynamic PM modes as failing.
...
Here's an example where things worked:
http://www.pwsan.com/omap/testlogs/test_v3.10/20130717134228/pm/3530es3beagl...
In this one, it can be seen that the CORE counts transitioned from:
core_pwrdm (ON),OFF:0,RET:2,INA:0,ON:3,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
to
core_pwrdm (ON),OFF:0,RET:10,INA:0,ON:11,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
between the retention suspend/resume test ending and the dynamic retention idle test ending.
Hmm I think the difference with the working v3.10 one is that you have root=/dev/mmcblk0p2 instead of root=/dev/nfs. As the Ethernet on beagle is on the USB EHCI, this is still blocking the deeper idle states AFAIK.
Care to test -rc7 with root=/dev/mmcblk0p2 to see if that works?
On the am37xx-evm nfsroot will work as it's on the GPMC bus.
Regards,
Tony