diff options
| author | Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> | 2020-06-23 21:49:16 +0100 |
|---|---|---|
| committer | Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> | 2020-06-26 10:13:51 +0100 |
| commit | 167f1667b120ddac301163da64b57b19ce7cf622 (patch) | |
| tree | 428bd195a3aa3991e33924f23419b50cf4747868 /hw/input/adb-mouse.c | |
| parent | bcaaefdbb2167858d3b92745b79473deb49c417a (diff) | |
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>
Diffstat (limited to 'hw/input/adb-mouse.c')
| -rw-r--r-- | hw/input/adb-mouse.c | 48 |
1 files changed, 28 insertions, 20 deletions
diff --git a/hw/input/adb-mouse.c b/hw/input/adb-mouse.c index aeba41bddd..78b6f5030c 100644 --- a/hw/input/adb-mouse.c +++ b/hw/input/adb-mouse.c @@ -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; @@ -145,27 +155,25 @@ 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: - * 0x01: Classic Apple Mouse Protocol / 100 cpi operations - * 0x02: Classic Apple Mouse Protocol / 200 cpi operations - * we don't support handlers (at least): - * 0x03: Mouse systems A3 trackball - * 0x04: Extended Apple Mouse Protocol - * 0x2f: Microspeed mouse - * 0x42: Macally - * 0x5f: Microspeed mouse - * 0x66: Microspeed mouse - */ - if (buf[2] == 1 || buf[2] == 2) { - d->handler = buf[2]; - } - - trace_adb_mouse_request_change_addr_and_handler( - d->devaddr, d->handler); + d->devaddr = buf[1] & 0xf; + /* + * 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): + * 0x03: Mouse systems A3 trackball + * 0x04: Extended Apple Mouse Protocol + * 0x2f: Microspeed mouse + * 0x42: Macally + * 0x5f: Microspeed mouse + * 0x66: Microspeed mouse + */ + if (buf[2] == 1 || buf[2] == 2) { + d->handler = buf[2]; } + + trace_adb_mouse_request_change_addr_and_handler(d->devaddr, + d->handler); break; } } |