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-rw-r--r--hw/misc/mac_via.c78
1 files changed, 27 insertions, 51 deletions
diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c
index 8810eb9..4914cb8 100644
--- a/hw/misc/mac_via.c
+++ b/hw/misc/mac_via.c
@@ -609,7 +609,6 @@ static void adb_via_poll(void *opaque)
uint8_t obuf[9];
uint8_t *data = &s->sr;
int olen;
- uint16_t pending;
/*
* Setting vADBInt below indicates that an autopoll reply has been
@@ -618,36 +617,36 @@ static void adb_via_poll(void *opaque)
*/
adb_autopoll_block(adb_bus);
- m->adb_data_in_index = 0;
- m->adb_data_out_index = 0;
- olen = adb_poll(adb_bus, obuf, adb_bus->autopoll_mask);
-
- if (olen > 0) {
- /* Autopoll response */
- *data = obuf[0];
- olen--;
- memcpy(m->adb_data_in, &obuf[1], olen);
- m->adb_data_in_size = olen;
+ if (m->adb_data_in_size > 0 && m->adb_data_in_index == 0) {
+ /*
+ * For older Linux kernels that switch to IDLE mode after sending the
+ * ADB command, detect if there is an existing response and return that
+ * as a a "fake" autopoll reply or bus timeout accordingly
+ */
+ *data = m->adb_data_out[0];
+ olen = m->adb_data_in_size;
s->b &= ~VIA1B_vADBInt;
qemu_irq_raise(m->adb_data_ready);
- } else if (olen < 0) {
- /* Bus timeout (device does not exist) */
- *data = 0xff;
- s->b |= VIA1B_vADBInt;
- adb_autopoll_unblock(adb_bus);
} else {
- pending = adb_bus->pending & ~(1 << (m->adb_autopoll_cmd >> 4));
+ /*
+ * Otherwise poll as normal
+ */
+ m->adb_data_in_index = 0;
+ m->adb_data_out_index = 0;
+ olen = adb_poll(adb_bus, obuf, adb_bus->autopoll_mask);
+
+ if (olen > 0) {
+ /* Autopoll response */
+ *data = obuf[0];
+ olen--;
+ memcpy(m->adb_data_in, &obuf[1], olen);
+ m->adb_data_in_size = olen;
- if (pending) {
- /*
- * Bus timeout (device exists but another device has data). Block
- * autopoll so the OS can read out the first EVEN and first ODD
- * byte to determine bus timeout and SRQ status
- */
- *data = m->adb_autopoll_cmd;
s->b &= ~VIA1B_vADBInt;
-
+ qemu_irq_raise(m->adb_data_ready);
+ } else {
+ *data = m->adb_autopoll_cmd;
obuf[0] = 0xff;
obuf[1] = 0xff;
olen = 2;
@@ -655,12 +654,8 @@ static void adb_via_poll(void *opaque)
memcpy(m->adb_data_in, obuf, olen);
m->adb_data_in_size = olen;
+ s->b &= ~VIA1B_vADBInt;
qemu_irq_raise(m->adb_data_ready);
- } else {
- /* Bus timeout (device exists but no other device has data) */
- *data = 0;
- s->b |= VIA1B_vADBInt;
- adb_autopoll_unblock(adb_bus);
}
}
@@ -783,27 +778,8 @@ static void adb_via_receive(MacVIAState *s, int state, uint8_t *data)
return;
case ADB_STATE_IDLE:
- /*
- * Since adb_request() will have already consumed the data from the
- * device, we must detect this extra state change and re-inject the
- * reponse as either a "fake" autopoll reply or bus timeout
- * accordingly
- */
- if (s->adb_data_in_index == 0) {
- if (adb_bus->status & ADB_STATUS_BUSTIMEOUT) {
- *data = 0xff;
- ms->b |= VIA1B_vADBInt;
- qemu_irq_raise(s->adb_data_ready);
- } else if (s->adb_data_in_size > 0) {
- adb_bus->status = ADB_STATUS_POLLREPLY;
- *data = s->adb_autopoll_cmd;
- ms->b &= ~VIA1B_vADBInt;
- qemu_irq_raise(s->adb_data_ready);
- }
- } else {
- ms->b |= VIA1B_vADBInt;
- adb_autopoll_unblock(adb_bus);
- }
+ ms->b |= VIA1B_vADBInt;
+ adb_autopoll_unblock(adb_bus);
trace_via1_adb_receive("IDLE", *data,
(ms->b & VIA1B_vADBInt) ? "+" : "-", adb_bus->status,