diff options
| -rw-r--r-- | synaptics.c | 75 |
1 files changed, 41 insertions, 34 deletions
diff --git a/synaptics.c b/synaptics.c index c8344fc..1e68622 100644 --- a/synaptics.c +++ b/synaptics.c @@ -1288,6 +1288,7 @@ QueryHardware (LocalDevicePtr local) } para->isSynaptics = priv->isSynaptics; + priv->protoBufTail = 0; if(!priv->isSynaptics) { xf86Msg(X_PROBED, "%s no synaptics touchpad, data piped to repeater fifo\n", local->name); synaptics_reset(local->fd); @@ -1523,12 +1524,43 @@ SynapticsParseRawPacket(LocalDevicePtr local, SynapticsPrivatePtr priv, return Success; } +/* + * Decide if the current packet stored in priv->protoBuf is valid. + */ +static Bool +PacketOk(SynapticsPrivatePtr priv) +{ + unsigned char *buf = priv->protoBuf; + int newabs = SYN_MODEL_NEWABS(priv->model_id); + + if (newabs ? ((buf[0] & 0xC8) != 0x80) : ((buf[0] & 0xC0) != 0xC0)) { + DBG(4, ErrorF("Synaptics driver lost sync at 1st byte\n")); + return FALSE; + } + + if (!newabs && ((buf[1] & 0x60) != 0x00)) { + DBG(4, ErrorF("Synaptics driver lost sync at 2nd byte\n")); + return FALSE; + } + + if ((newabs ? ((buf[3] & 0xc8) != 0xc0) : ((buf[3] & 0xc0) != 0x80))) { + DBG(4, ErrorF("Synaptics driver lost sync at 4th byte\n")); + return FALSE; + } + + if (!newabs && ((buf[4] & 0x60) != 0x00)) { + DBG(4, ErrorF("Synaptics driver lost sync at 5th byte\n")); + return FALSE; + } + + return TRUE; +} + static Bool SynapticsGetPacket(LocalDevicePtr local, SynapticsPrivatePtr priv) { int count = 0; int c; - int newabs = SYN_MODEL_NEWABS(priv->model_id); unsigned char u; while((c = XisbRead(priv->buffer)) >= 0) { @@ -1564,41 +1596,16 @@ SynapticsGetPacket(LocalDevicePtr local, SynapticsPrivatePtr priv) priv->protoBuf[priv->protoBufTail++] = u; - /* check first byte */ - if(priv->protoBufTail == 1) - { - if (newabs ? ((u & 0xC8) != 0x80) : ((u & 0xC0) != 0xC0)) - { + /* Check that we have a valid packet. If not, we are out of sync, + so we throw away the first byte in the packet.*/ + if (priv->protoBufTail >= 6) { + if (!PacketOk(priv)) { + int i; priv->inSync = FALSE; - priv->protoBufTail = 0; - DBG(4, ErrorF("Synaptics driver lost sync at 1st byte\n")); - continue; - } - } - /* for old protocol check 2nd and 5th byte */ - if (!newabs && ((priv->protoBufTail == 2) || (priv->protoBufTail == 5)) && - ((u & 0x60) != 0x00)) - { - if (priv->protoBufTail == 2) - { - DBG(4, ErrorF("Synaptics driver lost sync at 2nd byte\n")); - } - else - { - DBG(4, ErrorF("Synaptics driver lost sync at 5th byte\n")); + for (i = 0; i < priv->protoBufTail - 1; i++) + priv->protoBuf[i] = priv->protoBuf[i + 1]; + priv->protoBufTail--; } - priv->inSync = FALSE; - priv->protoBufTail = 0; - continue; - } - /* check 4th byte */ - if((priv->protoBufTail == 4) && - (newabs ? ((u & 0xc8) != 0xc0) : ((u & 0xc0) != 0x80))) - { - priv->inSync = FALSE; - priv->protoBufTail = 0; - DBG(4, ErrorF("Synaptics driver lost sync at 4th byte\n")); - continue; } if(priv->protoBufTail >= 6) |