adb: add autopoll_blocked variable to block autopoll

Whilst autopoll is enabled it is necessary to prevent the ADB buffer contents
from being overwritten until the host has read back the response in its
entirety.

Add adb_autopoll_block() and adb_autopoll_unblock() functions in preparation
for ensuring that the ADB buffer contents are protected for explicit ADB
requests.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200623204936.24064-16-mark.cave-ayland@ilande.co.uk>

diff --git a/hw/input/adb.c b/hw/input/adb.c
index b3ad7c5fca4a1aa27ae1ee5ebeb3170dbff7d412..70aa1f457045926dca8e0aa0f0cc0cf75fee6797 100644 (file)
--- a/hw/input/adb.c
+++ b/hw/input/adb.c
@@ -157,6 +157,26 @@ void adb_set_autopoll_mask(ADBBusState *s, uint16_t mask)
     }
 }
 
+void adb_autopoll_block(ADBBusState *s)
+{
+    s->autopoll_blocked = true;
+
+    if (s->autopoll_enabled) {
+        timer_del(s->autopoll_timer);
+    }
+}
+
+void adb_autopoll_unblock(ADBBusState *s)
+{
+    s->autopoll_blocked = false;
+
+    if (s->autopoll_enabled) {
+        timer_mod(s->autopoll_timer,
+                  qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                  s->autopoll_rate_ms);
+    }
+}
+
 static void adb_autopoll(void *opaque)
 {
     ADBBusState *s = opaque;
@@ -184,6 +204,7 @@ static const VMStateDescription vmstate_adb_bus = {
         VMSTATE_BOOL(autopoll_enabled, ADBBusState),
         VMSTATE_UINT8(autopoll_rate_ms, ADBBusState),
         VMSTATE_UINT16(autopoll_mask, ADBBusState),
+        VMSTATE_BOOL(autopoll_blocked, ADBBusState),
         VMSTATE_END_OF_LIST()
     }
 };

diff --git a/include/hw/input/adb.h b/include/hw/input/adb.h
index cff264739cd74d1be911cd9fbce75abdf9c7f1be..bb75a7b1e34f019e1ed1019520d74170a457aedc 100644 (file)
--- a/include/hw/input/adb.h
+++ b/include/hw/input/adb.h
@@ -86,6 +86,7 @@ struct ADBBusState {
 
     QEMUTimer *autopoll_timer;
     bool autopoll_enabled;
+    bool autopoll_blocked;
     uint8_t autopoll_rate_ms;
     uint16_t autopoll_mask;
     void (*autopoll_cb)(void *opaque);
@@ -96,6 +97,9 @@ int adb_request(ADBBusState *s, uint8_t *buf_out,
                 const uint8_t *buf, int len);
 int adb_poll(ADBBusState *s, uint8_t *buf_out, uint16_t poll_mask);
 
+void adb_autopoll_block(ADBBusState *s);
+void adb_autopoll_unblock(ADBBusState *s);
+
 void adb_set_autopoll_enabled(ADBBusState *s, bool enabled);
 void adb_set_autopoll_rate_ms(ADBBusState *s, int rate_ms);
 void adb_set_autopoll_mask(ADBBusState *s, uint16_t mask);