On Mon, 10 Dec 2012, Leo Yan wrote:
Here i also have some questions for big.LITTLE's coherency. so far, my working are mainly based on the fast model; but i found on fast model the coherency behavior is very sensitive.
Let's see my experiment on fast model: I used Nico's DCSCB patch for the core run into LPM;
Which one? If you are using the bL_cluster_pm branch, please note that it is lagging behind current development and probably has some bugs. I'd suggest you look at the tc2_pm_api branch which has support for both TC2 and RTSM.
sometimes during A15 core want to run into reset state, it need flush its L1 cache to inner sharable PoU, then it's very easily to let A7 get in-consistent data and introduce the kernel panic. But after i commented out A15's flush operations and just let A15 core run into infinite loop, then the system is stable, and the kernel panic issue will dismiss. So i believe A7 core has not get the coherence cache data so that it will introduce the kernel panic.
Please report back if you still see this happening with the above branch.
Nicolas