now make a test to know how long it take enter gic_handle_irq when extern interruption is coming.
GPIO5_3(is configured interrupt gpio) is connected to ADC_RDY(32Khz frequency output)
in-gpio147 and out-gpio146 is controled in gic_handle_irq.see the following:
static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
gpio_set_value(147, atomic_read(&intr_probe)%2);//interrupt is coming,gpio147 output level is flipped
} while (irqnr != ICC_IAR1_EL1_SPURIOUS);
discovery sometimes lost data, later found, when the interrupt comes to enter gic_handle_irq too late.below is grasping the underlying data waveform.how to optimize.thanks.
standard linux can not guarantee fixed interrupt latencies, in general one can try to analyze
it placing gpio toggling in code and observing it with oscilloscope, For low latency linux one can consider
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