[19/75] Input: synaptics - fix touchpad not working after S2R on Vostro V13

[Greg KH]

3.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>

commit 8521478f67e95ada4e87970c7b41e504c724b2cf upstream.

Synaptics touchpads on several Dell laptops, particularly Vostro V13
systems, may not respond properly to PS/2 commands and queries immediately
after resuming from suspend to RAM. This leads to unresponsive touchpad
after suspend/resume cycle.

Adding a 1-second delay after resetting the device allows touchpad to
finish initializing (calibrating?) and start reacting properly.

Reported-by: Daniel Manrique <daniel.manrique@xxxxxxxxxxxxx>
Tested-by: Daniel Manrique <daniel.manrique@xxxxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/input/mouse/synaptics.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -24,6 +24,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/delay.h>
 #include <linux/dmi.h>
 #include <linux/input/mt.h>
 #include <linux/serio.h>
@@ -786,6 +787,16 @@ static int synaptics_reconnect(struct ps
 
 	do {
 		psmouse_reset(psmouse);
+		if (retry) {
+			/*
+			 * On some boxes, right after resuming, the touchpad
+			 * needs some time to finish initializing (I assume
+			 * it needs time to calibrate) and start responding
+			 * to Synaptics-specific queries, so let's wait a
+			 * bit.
+			 */
+			ssleep(1);
+		}
 		error = synaptics_detect(psmouse, 0);
 	} while (error && ++retry < 3);
 


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