/* Takes a raw vector/trap number (32-47) */
int pic_check_spurious(int trap_nr)
{
if (trap_nr == PIC1_SPURIOUS && !(pic_get_isr() & (1 << 7))) {
++ pic1_spurious_irqs;
return 1;
}
if (trap_nr == PIC2_SPURIOUS && !(pic_get_isr() & (1 << 15))) {
++ pic2_spurious_irqs;
pic_send_eoi(PIC1_OFFSET + 2);
return 1;
}
return 0;
}
/* Takes a raw vector/trap number (32-47), not a device IRQ (0-15) */
bool pic_check_spurious(int trap_nr)
{
/* the PIC may send spurious irqs via one of the chips irq 7. if the isr
* doesn't show that irq, then it was spurious, and we don't send an eoi.
* Check out http://wiki.osdev.org/8259_PIC#Spurious_IRQs */
if ((trap_nr == PIC1_SPURIOUS) && !(pic_get_isr() & (1 << 7))) {
printd("Spurious PIC1 irq!\n"); /* want to know if this happens */
return TRUE;
}
if ((trap_nr == PIC2_SPURIOUS) && !(pic_get_isr() & (1 << 15))) {
printd("Spurious PIC2 irq!\n"); /* want to know if this happens */
/* for the cascaded PIC, we *do* need to send an EOI to the master's
* cascade irq (2). */
pic_send_eoi(2 + PIC1_OFFSET);
return TRUE;
}
return FALSE;
}
INLINE int pic_is_spurious(unsigned irq) {
uint16_t isr = pic_get_isr();
if (irq == 7) return isr != 128;
else if (irq == 15) {
if (isr != 0x8004) {
pic_eoi(2);
return 0;
} else return 1;
} else return 0;
}
