Auto-adjust edges if values fall outside queried min/max ranges. (#21001)

The kernel provides min/max for x/y values but still allows devices to send
coordinates outside this range. If the edges are autodetected, re-adjust the
edge settings to fit within the new effective min/max range.

When the edges change the property needs to be updated accordingly. This
can't be done immediately as changing properties requires mallocs and
HandleState is called during the signal handler.
Instead, set a timer to be called when the server isn't busy and update the
property then. The delay between setting the timer and sending the property
notify event also reduces the number of events sent, the property event
includes the latest state only.

If the edges were configured by the user, don't re-adjust.
This obsoletes the SpecialScrollAreaRight option as it provides the same
functionality, without the side-effects triggering 21001.

X.Org Bug 21001 <http://bugs.freedesktop.org/show_bug.cgi?id=21001>

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

3 files changed, 153 insertions, 35 deletions

diff --git a/src/properties.c b/src/properties.c
index 70b59e0..64dbc9e 100644
--- a/src/properties.c
+++ b/src/properties.c
@@ -617,5 +617,22 @@ SetProperty(DeviceIntPtr dev, Atom property, XIPropertyValuePtr prop,
     return Success;
 }
 
+void
+SetEdgeProperty(LocalDevicePtr local)
+{
+    SynapticsPrivate *priv = (SynapticsPrivate*)local->private;
+    SynapticsParameters *para = &priv->synpara;
+    uint32_t values[4];
+
+    values[0] = para->left_edge;
+    values[1] = para->right_edge;
+    values[2] = para->top_edge;
+    values[3] = para->bottom_edge;
+
+    XIChangeDeviceProperty(local->dev, prop_edges, XA_INTEGER, 32,
+                           PropModeReplace, 4, values, FALSE);
+}
+
+
 #endif
 
diff --git a/src/synaptics.c b/src/synaptics.c
index b100e5e..0a3a21a 100644
--- a/src/synaptics.c
+++ b/src/synaptics.c
@@ -82,17 +82,6 @@
 #include <xserver-properties.h>
 #endif
 
-typedef enum {
-    BOTTOM_EDGE = 1,
-    TOP_EDGE = 2,
-    LEFT_EDGE = 4,
-    RIGHT_EDGE = 8,
-    LEFT_BOTTOM_EDGE = BOTTOM_EDGE | LEFT_EDGE,
-    RIGHT_BOTTOM_EDGE = BOTTOM_EDGE | RIGHT_EDGE,
-    RIGHT_TOP_EDGE = TOP_EDGE | RIGHT_EDGE,
-    LEFT_TOP_EDGE = TOP_EDGE | LEFT_EDGE
-} edge_type;
-
 #define MAX(a, b) (((a)>(b))?(a):(b))
 #define MIN(a, b) (((a)<(b))?(a):(b))
 #define TIME_DIFF(a, b) ((int)((a)-(b)))
@@ -134,6 +123,7 @@ static void ReadDevDimensions(LocalDevicePtr);
 void InitDeviceProperties(LocalDevicePtr local);
 int SetProperty(DeviceIntPtr dev, Atom property, XIPropertyValuePtr prop,
                 BOOL checkonly);
+int SetEdgeProperty(LocalDevicePtr local);
 #endif
 
 InputDriverRec SYNAPTICS = {
@@ -450,6 +440,16 @@ static void set_default_parameters(LocalDevicePtr local)
     horizTwoFingerScroll = FALSE;
 
     /* set the parameters */
+    priv->edges_forced = 0;
+    if (xf86CheckIfOptionUsedByName(opts, "LeftEdge"))
+        priv->edges_forced |= LEFT_EDGE;
+    if (xf86CheckIfOptionUsedByName(opts, "RightEdge"))
+        priv->edges_forced |= RIGHT_EDGE;
+    if (xf86CheckIfOptionUsedByName(opts, "TopEdge"))
+        priv->edges_forced |= TOP_EDGE;
+    if (xf86CheckIfOptionUsedByName(opts, "BottomEdge"))
+        priv->edges_forced |= BOTTOM_EDGE;
+
     pars->left_edge = xf86SetIntOption(opts, "LeftEdge", l);
     pars->right_edge = xf86SetIntOption(opts, "RightEdge", r);
     pars->top_edge = xf86SetIntOption(opts, "TopEdge", t);
@@ -469,11 +469,6 @@ static void set_default_parameters(LocalDevicePtr local)
     pars->scroll_dist_vert = xf86SetIntOption(opts, "VertScrollDelta", horizScrollDelta);
     pars->scroll_dist_horiz = xf86SetIntOption(opts, "HorizScrollDelta", vertScrollDelta);
     pars->scroll_edge_vert = xf86SetBoolOption(opts, "VertEdgeScroll", vertEdgeScroll);
-    if (xf86CheckIfOptionUsedByName(opts, "RightEdge")) {
-      pars->special_scroll_area_right  = FALSE;
-    } else {
-      pars->special_scroll_area_right  = xf86SetBoolOption(opts, "SpecialScrollAreaRight", TRUE);
-    }
     pars->scroll_edge_horiz = xf86SetBoolOption(opts, "HorizEdgeScroll", horizEdgeScroll);
     pars->scroll_edge_corner = xf86SetBoolOption(opts, "CornerCoasting", FALSE);
     pars->scroll_twofinger_vert = xf86SetBoolOption(opts, "VertTwoFingerScroll", vertTwoFingerScroll);
@@ -554,6 +549,12 @@ SynapticsPreInit(InputDriverPtr drv, IDevPtr dev, int flags)
 	return NULL;
     }
 
+    priv->property_notify_timer = TimerSet(NULL, 0, 0, NULL, NULL);
+    if (!priv->property_notify_timer) {
+	xfree(priv);
+	return NULL;
+    }
+
     /* Allocate a new InputInfoRec and add it to the head xf86InputDevs. */
     local = xf86AllocateInput(drv, 0);
     if (!local) {
@@ -618,8 +619,6 @@ SynapticsPreInit(InputDriverPtr drv, IDevPtr dev, int flags)
 
     set_default_parameters(local);
 
-    priv->largest_valid_x = MIN(priv->synpara.right_edge, XMAX_NOMINAL);
-
     if (!alloc_param_data(local))
 	goto SetupProc_fail;
 
@@ -780,7 +779,9 @@ DeviceOff(DeviceIntPtr dev)
 
     if (local->fd != -1) {
 	TimerFree(priv->timer);
+	TimerFree(priv->property_notify_timer);
 	priv->timer = NULL;
+	priv->property_notify_timer = NULL;
 	xf86RemoveEnabledDevice(local);
         if (priv->proto_ops->DeviceOffHook)
             priv->proto_ops->DeviceOffHook(local);
@@ -1039,6 +1040,31 @@ edge_detection(SynapticsPrivate *priv, int x, int y)
     return edge;
 }
 
+#if GET_ABI_MAJOR(ABI_XINPUT_VERSION) >= 3
+/**
+ * Timer function. Called whenever the edges were auto-adjusted and the
+ * matching property must be updated to reflect the new state.
+ */
+static CARD32
+propertyTimerFunc(OsTimerPtr timer, CARD32 now, pointer arg)
+{
+    LocalDevicePtr local = (LocalDevicePtr)arg;
+    SynapticsPrivate *priv = (SynapticsPrivate*)local->private;
+    int sigstate;
+
+    if (!(priv->edges_forced & EDGE_CHANGE_WAITING))
+        return 0;
+
+    sigstate = xf86BlockSIGIO();
+
+    SetEdgeProperty(local);
+
+    priv->edges_forced &= ~(EDGE_CHANGED | EDGE_CHANGE_WAITING);
+    xf86UnblockSIGIO(sigstate);
+    return 0;
+}
+#endif
+
 static CARD32
 timerFunc(OsTimerPtr timer, CARD32 now, pointer arg)
 {
@@ -1111,6 +1137,16 @@ ReadInput(LocalDevicePtr local)
 
     if (newDelay)
 	priv->timer = TimerSet(priv->timer, 0, delay, timerFunc, local);
+
+#if GET_ABI_MAJOR(ABI_XINPUT_VERSION) >= 3
+    /* Set a timer to change the edges property ASAP if we auto-adjusted */
+    if ((priv->edges_forced & EDGE_CHANGED) &&
+        !(priv->edges_forced & EDGE_CHANGE_WAITING)) {
+	priv->property_notify_timer =
+	    TimerSet(priv->property_notify_timer, 0, 100, propertyTimerFunc, local);
+	priv->edges_forced |= EDGE_CHANGE_WAITING;
+    }
+#endif
 }
 
 static int
@@ -2119,22 +2155,65 @@ HandleState(LocalDevicePtr local, struct SynapticsHwState *hw)
 	hw->multi[2] = hw->multi[3] = FALSE;
     }
 
-    /*
-     * Some touchpads have a scroll wheel region where a very large X
-     * coordinate is reported. In this case for eliminate discontinuity,
-     * we adjust X and simulate new zone which adjacent to right edge.
-     */
-    if (hw->x <= XMAX_VALID) {
-	if (priv->largest_valid_x < hw->x)
-	    priv->largest_valid_x = hw->x;
-    } else {
-	hw->x = priv->largest_valid_x + 1;
-    /*
-     * If user didn't set right_edge manualy, auto-adjust to bounds of
-     * hardware scroll area.
-     */
-	if (para->special_scroll_area_right)
-	  priv->synpara.right_edge = priv->largest_valid_x;
+    /* The kernel doesn't clip into min/max, so auto-adjust the edges if we
+     * go beyond min/max */
+    if (hw->x > priv->maxx || hw->x < priv->minx ||
+        hw->y > priv->maxy || hw->y < priv->miny)
+    {
+        int l, r, t, b;
+        Bool changed = FALSE;
+
+        if (hw->x > priv->maxx && !(priv->edges_forced & RIGHT_EDGE))
+        {
+            priv->maxx = hw->x;
+            changed = TRUE;
+        } else if (hw->x < priv->minx && !(priv->edges_forced & LEFT_EDGE))
+        {
+            priv->minx = hw->x;
+            changed = TRUE;
+        }
+
+        if (hw->y > priv->maxy && !(priv->edges_forced & BOTTOM_EDGE))
+        {
+            priv->maxy = hw->y;
+            changed = TRUE;
+        } else if (hw->y < priv->miny && !(priv->edges_forced & TOP_EDGE))
+        {
+            priv->miny = hw->y;
+            changed = TRUE;
+        }
+
+        if (changed)
+        {
+            Bool adjusted = FALSE;
+            calculate_edge_widths(priv, &l, &r, &t, &b);
+            if (!(priv->edges_forced & LEFT_EDGE))
+            {
+                para->left_edge = l;
+                adjusted = TRUE;
+            }
+            if (!(priv->edges_forced & RIGHT_EDGE))
+            {
+                para->right_edge = r;
+                adjusted = TRUE;
+            }
+            if (!(priv->edges_forced & TOP_EDGE))
+            {
+                para->top_edge = t;
+                adjusted = TRUE;
+            }
+            if (!(priv->edges_forced & BOTTOM_EDGE))
+            {
+                para->bottom_edge = b;
+                adjusted = TRUE;
+            }
+
+            /* We're inside a signal handler, can't change the edges
+             * property directly. Instead, set a flag and (later) a timer to
+             * set the property ASAP */
+            if (adjusted)
+                priv->edges_forced |= EDGE_CHANGED;
+        }
     }
 
     edge = edge_detection(priv, hw->x, hw->y);
diff --git a/src/synapticsstr.h b/src/synapticsstr.h
index d2ff57c..87af600 100644
--- a/src/synapticsstr.h
+++ b/src/synapticsstr.h
@@ -86,6 +86,23 @@ enum TouchpadModel {
     MODEL_APPLETOUCH
 };
 
+typedef enum {
+    BOTTOM_EDGE = 1,
+    TOP_EDGE = 2,
+    LEFT_EDGE = 4,
+    RIGHT_EDGE = 8,
+    LEFT_BOTTOM_EDGE = BOTTOM_EDGE | LEFT_EDGE,
+    RIGHT_BOTTOM_EDGE = BOTTOM_EDGE | RIGHT_EDGE,
+    RIGHT_TOP_EDGE = TOP_EDGE | RIGHT_EDGE,
+    LEFT_TOP_EDGE = TOP_EDGE | LEFT_EDGE,
+
+    /* EDGE_CHANGED and EDGE_CHANGED_WAITING are flags to signal that there
+     * at least one edge has changed and that there is a property notify
+     * event waiting to be sent, respectively. */
+    EDGE_CHANGED = 16,
+    EDGE_CHANGE_WAITING = 32
+} edge_type;
+
 typedef struct _SynapticsParameters
 {
     /* Parameter data */
@@ -169,7 +186,6 @@ typedef struct _SynapticsPrivateRec
 
     SynapticsMoveHistRec move_hist[SYNAPTICS_MOVE_HISTORY]; /* movement history */
     int hist_index;			/* Last added entry in move_hist[] */
-    int largest_valid_x;		/* Largest valid X coordinate seen so far */
     int scroll_y;			/* last y-scroll position */
     int scroll_x;			/* last x-scroll position */
     double scroll_a;			/* last angle-scroll position */
@@ -219,6 +235,12 @@ typedef struct _SynapticsPrivateRec
     Bool has_pressure;			/* device reports pressure */
 
     enum TouchpadModel model;          /* The detected model */
+
+    /* edges_forces is set to RIGHT_EDGE | LEFT_EDGE | ... when the matching
+     * edge is specified in the xorg.conf. When the edges are auto-adjusted,
+     * edges_forces may be flagged EDGE_CHANGED and EDGE_CHANGED_WAITING */
+    int edges_forced;                   /* edges set manually? RIGHT_EDGE | LEFT_EDGE | ... */
+    OsTimerPtr property_notify_timer;   /* For sending off property notify events */
 } SynapticsPrivate;
 
 #endif /* _SYNAPTICSSTR_H_ */