Posted on March 25, 2018 at 08:33This one took me a while to troubleshoot. The unit will literally run for hours without crashing, then sometimes only five minutes and crash without changing any code.
I think the issue has something to do with serial_dll. Our program has a PIT that runs at 50Hz. The PIT handler is used as an interrupt that periodically loads data onto an RS-232 port. I've boiled down a program that runs, verse one that eventually crashes.
NOTE: I feel like this is *not* a IVOR12 issue, as sometimes the IVOR4 and IVOR1 are
triggered. I think this issue is related to interrupts, most notably -
osalEnterCritical(); which is called in sd_lld_write();
This program crashes periodically (very simplified version for investigation purposes):
<<<
int main(void)
{
componentsInit();
irqIsrEnable();
sd_lld_start(&SD1, NULL); // baud 19277
pit_lld_start(&PITD, pit_config); // 50Hz
pit_lld_channel_start(&PITD, 2U);
for ( ; ; )
{
}
}
uint8_t message[]= 'Hello World!\r\n';
// PIT
@
50Hz
void low_speed_PIT(void)
{
sd_lld_write(&SD1,message,(uint16_t)(sizeof(message)/sizeof(message[0])));
}
>>>
This program runs perfectly
(note that sd_lld is not called within PIT):
<<<
int main(void)
{
componentsInit();
irqIsrEnable();
sd_lld_start(&SD1, NULL);
// baud
19277
for ( ; ; )
{
sd_lld_write(&SD1,message,(uint16_t)(sizeof(message)/sizeof(message[0])));
osalThreadDelayMilliseconds(19);
}
}
>>>
The issue seems (not obviously) related to putting serial data inside a PIT. I am guessing that this is a
priority issue. Is this an uncommon practice? I think it is corrupting the interrupt scheme somehow.
Cheers,
~Matt
