From 9939375c282a0f97afa69dc6799d3c77aaf7d544 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 20 Jan 2015 17:23:48 +0100 Subject: sb16: fix interrupt acknowledgement SoundBlaster 16 emulation is very broken and consumes a lot of CPU, but a small fix was suggested offlist and it is enough to fix some games. I got Epic Pinball to work with the "SoundBlaster Clone" option. The processing of the interrupt register is wrong due to two missing "not"s. This causes the interrupt flag to remain set even after the Acknowledge ports have been read (0x0e and 0x0f). The line was introduced by commit 85571bc (audio merge (malc), 2004-11-07), but the code might have been broken before because I did not look closely at the huge patches from 10 years ago. Reported-by: Joshua Bair Cc: Gerd Hoffmann Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini Signed-off-by: Gerd Hoffmann --- hw/audio/sb16.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/audio/sb16.c b/hw/audio/sb16.c index bda26d0..444eb9e 100644 --- a/hw/audio/sb16.c +++ b/hw/audio/sb16.c @@ -999,7 +999,7 @@ static IO_READ_PROTO (dsp_read) retval = (!s->out_data_len || s->highspeed) ? 0 : 0x80; if (s->mixer_regs[0x82] & 1) { ack = 1; - s->mixer_regs[0x82] &= 1; + s->mixer_regs[0x82] &= ~1; qemu_irq_lower (s->pic); } break; @@ -1008,7 +1008,7 @@ static IO_READ_PROTO (dsp_read) retval = 0xff; if (s->mixer_regs[0x82] & 2) { ack = 1; - s->mixer_regs[0x82] &= 2; + s->mixer_regs[0x82] &= ~2; qemu_irq_lower (s->pic); } break; -- cgit v1.1