Hi,
I currently meet a problem about disable interrupt in using MPC5748G only run on Core0, and all data and instruction cache are disabled.
When I try to disable the global interrupt, call the vPortMaskInterrupts, which raise the priority of INTC.CPR0, and set it to configMAX_API_CALL_INTERRUPT_PRIORITY, which is defined 8, the source code is following:
static portFORCE_INLINE void vPortMaskInterrupts( void )
{
#ifndef CODE_ANALYSIS
BaseType_t msr;
uint8_t i = 0;
// See MPC5746C RM Rev 3 section 21.8.5.2 "Ensuring coherency" (most restrictive rules)
// See MPC5646C RM Rev 5 section 19.10.4.2 "Ensuring coherency"
// See MPC5607B RM Rev 7.2 section 18.7.5.2 "Ensuring coherency"
// See MPC5604B RM Rev 8.2 section 16.7.5.2 "Ensuring coherency"
__asm__ volatile
(
"mfmsr %0 \n\t"
"wrteei 0 \n\t" // disable interrupts
: "=r" (msr)
);
/* Set current interrupt priority to max API priority */
portINTC_CPR = configMAX_API_CALL_INTERRUPT_PRIORITY;
i += 1; //just for test
__asm__ volatile
(
"mbar \n\t" // ensure INTC_CPR write completes before re-enabling interrupts
"wrtee %0 \n\t" // re-enable interrupts if they were previously enabled
"se_isync \n\t" // re-fetch Processor pipeline
: : "r" (msr)
);
#endif
}
The problem is when disable global interrupt and the after executes
portINTC_CPR = configMAX_API_CALL_INTERRUPT_PRIORITY,
the INTC.CPR really become 8, but after the next one step executed, it become 0 again whatever the code is.
The result is that it can't prevent the interrupts with priority below configMAX_API_CALL_INTERRUPT_PRIORITY happens.
As I know when set INTC.CPR0 to 8 before reset it to 0, any interrupts with priority below or equal to 8 should not happen.
Can anyone explain why this happens?
Thanks very much.
