[PATCH V2 driver/input/synaptics] For serial devices try reconnecting if device is wedged

[Egbert Eich]

From: Takashi Iwai <tiwai at suse.de>

Under some circumstances the synaptics device may be wedged when
coming back from a sleep state. Add some magic which tries to
detect this and reconnect.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Egbert Eich <eich at freedesktop.org>
---
v2: Avoid '_' at beginning of function name.

 src/eventcomm.c    |  3 ++-
 src/synaptics.c    | 56 +++++++++++++++++++++++++++++++++++++++++++++++-------
 src/synapticsstr.h |  3 +++
 3 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/src/eventcomm.c b/src/eventcomm.c
index 258a538..86b74cb 100644
--- a/src/eventcomm.c
+++ b/src/eventcomm.c
@@ -638,7 +638,8 @@ EventReadHwState(InputInfoPtr pInfo,
     }
 
     while (SynapticsReadEvent(pInfo, &ev)) {
-        switch (ev.type) {
+	priv->comm_read++;
+	switch (ev.type) {
         case EV_SYN:
             switch (ev.code) {
             case SYN_REPORT:
diff --git a/src/synaptics.c b/src/synaptics.c
index f0a8269..007d0bb 100644
--- a/src/synaptics.c
+++ b/src/synaptics.c
@@ -920,18 +920,30 @@ DeviceControl(DeviceIntPtr dev, int mode)
 }
 
 static int
-DeviceOn(DeviceIntPtr dev)
+doDeviceOn(InputInfoPtr pInfo)
 {
-    InputInfoPtr pInfo = dev->public.devicePrivate;
     SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
+    int n;
 
     DBG(3, "Synaptics DeviceOn called\n");
 
-    pInfo->fd = xf86OpenSerial(pInfo->options);
+    for (n = priv->retries; n >= 0; n--) {
+	pInfo->fd = xf86OpenSerial(pInfo->options);
+	if (pInfo->fd != -1)
+	    break;
+	if (n)
+	    xf86Msg(X_WARNING, "%s: cannot open input device - "
+		    "retrying %d more times\n", pInfo->name, n);
+    }
     if (pInfo->fd == -1) {
         xf86IDrvMsg(pInfo, X_WARNING, "cannot open input device\n");
         return !Success;
     }
+    /* This has succeeded once, so chances are the hardware *really* is present
+     * - this is not a hotplug device after all.
+     * Without trying really hard on some machines with some kernels the device
+     * won't be found after S3/S4 again. */
+    priv->retries = 4;
 
     if (priv->proto_ops->DeviceOnHook &&
         !priv->proto_ops->DeviceOnHook(pInfo, &priv->synpara))
@@ -956,11 +968,21 @@ DeviceOn(DeviceIntPtr dev)
     }
 
     xf86AddEnabledDevice(pInfo);
-    dev->public.on = TRUE;
 
     return Success;
 }
 
+static int
+DeviceOn(DeviceIntPtr dev)
+{
+    int ret = doDeviceOn(dev->public.devicePrivate);
+
+    if (ret == Success)
+	dev->public.on = TRUE;
+
+    return ret;
+}
+
 static void
 SynapticsReset(SynapticsPrivate * priv)
 {
@@ -995,9 +1017,8 @@ SynapticsReset(SynapticsPrivate * priv)
 }
 
 static int
-DeviceOff(DeviceIntPtr dev)
+_DeviceOff(InputInfoPtr pInfo)
 {
-    InputInfoPtr pInfo = dev->public.devicePrivate;
     SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
     Bool rc = Success;
 
@@ -1018,11 +1039,18 @@ DeviceOff(DeviceIntPtr dev)
         xf86CloseSerial(pInfo->fd);
         pInfo->fd = -1;
     }
-    dev->public.on = FALSE;
     return rc;
 }
 
 static int
+DeviceOff(DeviceIntPtr dev)
+{
+    int ret = _DeviceOff(dev->public.devicePrivate);
+    dev->public.on = FALSE;
+    return ret;
+}
+
+static int
 DeviceClose(DeviceIntPtr dev)
 {
     Bool RetValue;
@@ -1469,6 +1497,7 @@ ReadInput(InputInfoPtr pInfo)
 
     SynapticsResetTouchHwState(hw, FALSE);
 
+    priv->comm_read = 0;
     while (SynapticsGetHwState(pInfo, priv, hw)) {
         /* Semi-mt device touch slots do not track touches. When there is a
          * change in the number of touches, we must disregard the temporary
@@ -1487,6 +1516,19 @@ ReadInput(InputInfoPtr pInfo)
         newDelay = TRUE;
     }
 
+    if (!priv->comm_read) {
+        /* strange callback, check the device and reconnect if needed */
+	if (!priv->reconnecting) {
+	    priv->reconnecting = 1;
+	    xf86Msg(X_WARNING, "%s: reconnecting device...\n", pInfo->name);
+	    _DeviceOff(pInfo);
+	    usleep(100*1000);
+	    doDeviceOn(pInfo);
+	    xf86Msg(X_WARNING, "%s: reconnection done\n", pInfo->name);
+	} else
+	    priv->reconnecting = 0;
+    }
+
     if (newDelay) {
         priv->timer_time = GetTimeInMillis();
         priv->timer = TimerSet(priv->timer, 0, delay, timerFunc, pInfo);
diff --git a/src/synapticsstr.h b/src/synapticsstr.h
index 428befa..98d6552 100644
--- a/src/synapticsstr.h
+++ b/src/synapticsstr.h
@@ -204,6 +204,9 @@ struct _SynapticsPrivateRec {
     OsTimerPtr timer;           /* for tap processing, etc */
 
     struct CommData comm;
+    int comm_read;		/* for reconnection check */
+    int reconnecting;		/* for reconnection check */
+    int retries;
 
     struct SynapticsHwState *local_hw_state;    /* used in place of local hw state variables */
 
-- 
1.8.1.4