Allocate SynapticsHwStruct for local function use

SynapticsHwStruct (SHS) will soon include ValuatorMasks, which can only
be allocated on the heap. The input driver callbacks are called in
signal context, so we can't instantiate a new SHS when that occurs.
Since we only ever need one SHS, allocate one at device init time and
use it in place of local SHS instances.

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

2 files changed, 17 insertions, 7 deletions

diff --git a/src/synaptics.c b/src/synaptics.c
index a4c1e5a..e7deb9b 100644
--- a/src/synaptics.c
+++ b/src/synaptics.c
@@ -934,6 +934,7 @@ DeviceClose(DeviceIntPtr dev)
     TimerFree(priv->timer);
     priv->timer = NULL;
     free_shm_data(priv);
+    SynapticsHwStateFree(&priv->local_hw_state);
     return RetValue;
 }
 
@@ -1179,8 +1180,15 @@ no_touch:
 
     free(axes_labels);
 
+    priv->local_hw_state = SynapticsHwStateAlloc(priv);
+    if (!priv->local_hw_state)
+	return !Success;
+
     if (!alloc_shm_data(pInfo))
+    {
+	free(priv->local_hw_state);
 	return !Success;
+    }
 
     InitDeviceProperties(pInfo);
     XIRegisterPropertyHandler(pInfo->dev, SetProperty, NULL, NULL);
@@ -1310,15 +1318,15 @@ timerFunc(OsTimerPtr timer, CARD32 now, pointer arg)
 {
     InputInfoPtr pInfo = arg;
     SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
-    struct SynapticsHwState hw;
+    struct SynapticsHwState *hw = priv->local_hw_state;
     int delay;
     int sigstate;
 
     sigstate = xf86BlockSIGIO();
 
     priv->hwState.millis += now - priv->timer_time;
-    hw = priv->hwState;
-    delay = HandleState(pInfo, &hw, hw.millis, TRUE);
+    *hw = priv->hwState;
+    delay = HandleState(pInfo, hw, hw->millis, TRUE);
 
     priv->timer_time = now;
     priv->timer = TimerSet(priv->timer, 0, delay, timerFunc, pInfo);
@@ -1353,13 +1361,13 @@ static void
 ReadInput(InputInfoPtr pInfo)
 {
     SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
-    struct SynapticsHwState hw;
+    struct SynapticsHwState *hw = priv->local_hw_state;
     int delay = 0;
     Bool newDelay = FALSE;
 
-    while (SynapticsGetHwState(pInfo, priv, &hw)) {
-	priv->hwState = hw;
-	delay = HandleState(pInfo, &hw, hw.millis, FALSE);
+    while (SynapticsGetHwState(pInfo, priv, hw)) {
+	priv->hwState = *hw;
+	delay = HandleState(pInfo, hw, hw->millis, FALSE);
 	newDelay = TRUE;
     }
 
diff --git a/src/synapticsstr.h b/src/synapticsstr.h
index d3b8607..fff159c 100644
--- a/src/synapticsstr.h
+++ b/src/synapticsstr.h
@@ -201,6 +201,8 @@ typedef struct _SynapticsPrivateRec
 
     struct CommData comm;
 
+    struct SynapticsHwState *local_hw_state; /* used in place of local hw state variables */
+
     Bool absolute_events;               /* post absolute motion events instead of relative */
     SynapticsMoveHistRec move_hist[SYNAPTICS_MOVE_HISTORY]; /* movement history */
     int hist_index;			/* Last added entry in move_hist[] */