Am Tue, 28 Feb 2017 20:14:45 +0100 hat Matthijs van Duin matthijsvanduin@gmail.com geschrieben:
Hi,
I already had observed that there is some "memory effect" which has something to do with how fast and in which sequence power is (re)applied and so far I thought that the Palmas backup (supercap) has something to do with it.
Ah there's a supercap too? I hadn't even stopped to think about that one.. I've quite often seen strange memory effects, or "bistability" of some sort where it either boots fine (into u-boot at least) repeatedly, or utterly fails (often even without any message on console) repeatedly.
Hm, that's very weird and we should try to find out what happens here. It doesn't really sound like a hardware instability issue if the hardware works fine once you managed to boot it up.
I wonder if there are some parameters set that freeze the system and that aren't resetted properly...?
Yes, there must be something wrong with warm reset. If I "reboot" from Linux everything works well, up to Kernel starting... where nothing happens any more.
I've also noticed that the reset using shoulder button + power button rarely recovers the system from a wedged state (although it seems to work fine if the system is running fine).
What does the Shoulder-Button + Power Button do? Does it send some reset signal to the OMAP / Palmas? Or does it have it's own reset circuit?
The reset should ALWAYS work, especially when the system crashes or freezes. If the OMAP / PALMAS freezes and ignores the reset signal, then that's not really useful :)