Commit 8d484caa authored Oct 07, 2011 by Jan Kiszka Committed by Blue Swirl Oct 16, 2011

i8259: Fix poll command

This was probably never used so far: According to the spec, polling
means ack'ing the pending IRQ and setting its corresponding bit in isr.
Moreover, we have to signal a pending IRQ via bit 7 of the returned
value, and we must not return a spurious IRQ if none is pending.

This implements the poll command without the help of pic_poll_read which
is left untouched as pic_intack_read is still using it.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

parent b76750c1

hw/i8259.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -393,7 +393,13 @@ static uint64_t pic_ioport_read(void *opaque, target_phys_addr_t addr1,
		int ret;

		if (s->poll) {
		ret = pic_poll_read(s);
		ret = pic_get_irq(s);
		if (ret >= 0) {
		pic_intack(s, ret);
		ret \|= 0x80;
		} else {
		ret = 0;
		}
		s->poll = 0;
		} else {
		if (addr == 0) {