adb: fix adb-mouse read length and revert disable-reg3-direct-writes workaround

Commit 84051eb400 "adb: add property to disable direct reg 3 writes" introduced
a workaround for spurious writes to ADB register 3 when MacOS 9 enables
autopoll on the mouse device. Further analysis shows that the problem is that
only a partial request is sent, and since the len parameter is ignored then
stale data from the previous request is used causing the incorrect address
assignment.

Remove the disable-reg3-direct-writes workaround and instead check the length
parameter when the write is attempted, discarding the invalid request.

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: <20200623204936.24064-3-mark.cave-ayland@ilande.co.uk>

1 files changed, 0 insertions, 7 deletions

diff --git a/hw/input/adb.c b/hw/input/adb.c
index bf1bc30d19..d85278a7b7 100644
--- a/hw/input/adb.c
+++ b/hw/input/adb.c
@@ -118,18 +118,11 @@ static void adb_device_realizefn(DeviceState *dev, Error **errp)
     bus->devices[bus->nb_devices++] = d;
 }
 
-static Property adb_device_properties[] = {
-    DEFINE_PROP_BOOL("disable-direct-reg3-writes", ADBDevice,
-                     disable_direct_reg3_writes, false),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void adb_device_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
 
     dc->realize = adb_device_realizefn;
-    device_class_set_props(dc, adb_device_properties);
     dc->bus_type = TYPE_ADB_BUS;
 }