Commit 167f1667 authored by Mark Cave-Ayland's avatar Mark Cave-Ayland
Browse files

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



Commit 84051eb4 "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: default avatarMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: default avatarFinn Thain <fthain@telegraphics.com.au>
Acked-by: default avatarLaurent Vivier <laurent@vivier.eu>
Message-Id: <20200623204936.24064-3-mark.cave-ayland@ilande.co.uk>
parent bcaaefdb

hw/input/adb-kbd.c

+12 −14
Original line number Diff line number Diff line
@@ -259,10 +259,9 @@ static int adb_kbd_request(ADBDevice *d, uint8_t *obuf, 
                trace_adb_kbd_request_change_addr(d->devaddr);

                break;

            default:

                if (!d->disable_direct_reg3_writes) {

                d->devaddr = buf[1] & 0xf;



                    /* we support handlers:

                /*

                 * we support handlers:

                 * 1: Apple Standard Keyboard

                 * 2: Apple Extended Keyboard (LShift = RShift)

                 * 3: Apple Extended Keyboard (LShift != RShift)
@@ -273,7 +272,6 @@ static int adb_kbd_request(ADBDevice *d, uint8_t *obuf, 


                trace_adb_kbd_request_change_addr_and_handler(d->devaddr,

                                                              d->handler);

                }

                break;

            }

        }

hw/input/adb-mouse.c

+28 −20
Original line number Diff line number Diff line
@@ -135,6 +135,16 @@ static int adb_mouse_request(ADBDevice *d, uint8_t *obuf, 
        case 2:

            break;

        case 3:

            /*

             * MacOS 9 has a bug in its ADB driver whereby after configuring

             * the ADB bus devices it sends another write of invalid length

             * to reg 3. Make sure we ignore it to prevent an address clash

             * with the previous device.

             */

            if (len != 3) {

                return 0;

            }



            switch (buf[2]) {

            case ADB_CMD_SELF_TEST:

                break;
@@ -145,10 +155,9 @@ static int adb_mouse_request(ADBDevice *d, uint8_t *obuf, 
                trace_adb_mouse_request_change_addr(d->devaddr);

                break;

            default:

                if (!d->disable_direct_reg3_writes) {

                d->devaddr = buf[1] & 0xf;



                    /* we support handlers:

                /*

                 * we support handlers:

                 * 0x01: Classic Apple Mouse Protocol / 100 cpi operations

                 * 0x02: Classic Apple Mouse Protocol / 200 cpi operations

                 * we don't support handlers (at least):
@@ -163,9 +172,8 @@ static int adb_mouse_request(ADBDevice *d, uint8_t *obuf, 
                    d->handler = buf[2];

                }



                    trace_adb_mouse_request_change_addr_and_handler(

                        d->devaddr, d->handler);

                }

                trace_adb_mouse_request_change_addr_and_handler(d->devaddr,

                                                                d->handler);

                break;

            }

        }

hw/input/adb.c

+0 −7
Original line number Diff line number Diff line
@@ -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;

}

hw/ppc/mac_newworld.c

+0 −2
Original line number Diff line number Diff line
@@ -404,11 +404,9 @@ static void ppc_core99_init(MachineState *machine) 


        adb_bus = qdev_get_child_bus(dev, "adb.0");

        dev = qdev_new(TYPE_ADB_KEYBOARD);

        qdev_prop_set_bit(dev, "disable-direct-reg3-writes", true);

        qdev_realize_and_unref(dev, adb_bus, &error_fatal);



        dev = qdev_new(TYPE_ADB_MOUSE);

        qdev_prop_set_bit(dev, "disable-direct-reg3-writes", true);

        qdev_realize_and_unref(dev, adb_bus, &error_fatal);

    }

include/hw/input/adb.h

+0 −1
Original line number Diff line number Diff line
@@ -49,7 +49,6 @@ struct ADBDevice { 


    int devaddr;

    int handler;

    bool disable_direct_reg3_writes;

};



#define ADB_DEVICE_CLASS(cls) \