pstorage handler callback without scheduler?

RE: pstorage handler callback without scheduler?

Chris — Thu, 17 Sep 2015 02:35:06 GMT

Yes, sorry for the confusion. Initially I had none of the while() loop stuff at all and everything seemed to be working dandy. Then I figured I should wait for the clear to finish before calling the store, so I looked at examples and they had the while() power_manage() loop, so I added that, which obviously does not work in my case. Where it prints out '1' forever above, I commented it out.

So it looks like the best way to go is to convert this to use the scheduler, which I sort of tried yesterday, but then everything broke. I am not the original author of this code and am basically taking over a 'half-working' project - going through and fixing things.

Thanks for the help and look out for me asking questions about using the scheduler :-)

RE: pstorage handler callback without scheduler?

RK — Thu, 17 Sep 2015 02:11:18 GMT

but there's a call to power_manage() in the code you posted for 'store()' which is not your main loop. Or is that not your real code?

yes a timer timeout handler is called in interrupt context.

RE: pstorage handler callback without scheduler?

Chris — Thu, 17 Sep 2015 02:08:32 GMT

The only place I am calling power_manage() is from the main loop:

// Enter main loop.
for(;;) {
	power_manage();
}

I am assuming that a timer timeoutHandler() is an 'interrupt handler'? Then any function that gets called from inside the timeoutHandler() would be running with APP_HIGH interrupt priority? And any following functions that are called from within the initially-called function would also be APP_HIGH interrupt priority - creating a giant chain of APP_HIGH interrupt priority 'functions'? Then I see the problem...

RE: pstorage handler callback without scheduler?

RK — Thu, 17 Sep 2015 00:58:14 GMT

store(), I'm guessing that's called from an interrupt handler, one running with APP_HIGH interrupt priority. If that's the case you never leave the interrupt handler which means the lower-priority SWI which does all the event handling can never run, you've deadlocked yourself.

Don't put power_manage() in the interrupt handlers, put it in your main context, or run it at a lower interrupt priority (not a fan of that myself, interrupt handlers should be fast if possible). If you put it in your main thread then you'll have to keep some kind of state machine variables to tell you you have started a store() operation and are waiting for the pstorage_clear() to finish in order to do the store.

So no you don't need a scheduler, there's a ton of ways to do what you want, you may however find a scheduler, which runs in main thread context, it the easiest.

RE: pstorage handler callback without scheduler?

Chris — Wed, 16 Sep 2015 19:19:05 GMT

If I remove the while() loop, then I will get the printf from the device_cd_handler(), "pstorage_clear success".

With the while() loop in place, it gets stuck in there. Changing power_manage() to __wfe() made no difference. I changed it to this and it prints outs out '1' forever.

while(pstorageState) {
	//power_manage();
	//__wfe();
	SEGGER_RTT_printf(0, "pstorageState = %d\n", pstorageState);
}

I am asking again, just to make sure, is a scheduler required for this to work?

Thanks.

RE: pstorage handler callback without scheduler?

RK — Wed, 16 Sep 2015 09:33:53 GMT

Is device_cb_handler() being called by the pstorage module? If so is it setting the pStorageState variable? If you run, wait a second and then hit break in the debugger, what's the value of pStorageState? If it's '1' then the issue is you're not getting out of power_manage().

If that's the case - change it to __wfe()