RL-ARM: Possible Reasons for OS_ERR_FIFO_OVF Status
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On rare occasions, os_error() is being called with OS_ERR_FIFO_OVF. What can be the reason for this?
The OS_ERR_FIFO_OVF occurs when the FIFO queue for post-processing events sent via isr_xxx() functions becomes full. In this case, events will be lost. To inform the user about this critical situation, os_error() is called.
Interrupts can't access critical RTX resources. Because of that, such actions must be queued and later processed by the RTX. isr_xxx() functions will also trigger an RTX interrupt that runs when the current interrupt handler finishes.
This FIFO queue size is configurable in the RTX_Config. But selecting the maximum size will not always help if the RTX does not get the chance to process the FIFO queue. So possible reasons for the error are:
Check your application against the possible reasons mentioned above and avoid them. This should give RTX sufficient time to post-process the FIFO queue and the OS_ERR_FIFO_OVF error will not occur.
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Last Reviewed: Thursday, November 12, 2020
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