Input: synaptics - fix touchpad not working after S2R on Vostro V13

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 <[email protected]> Tested-by: Daniel Manrique <[email protected]> Cc: [email protected] Signed-off-by: Dmitry Torokhov <[email protected]>
redpig · Dec 12, 2011 · 8521478 · 8521478
1 parent 3a7f8fb
commit 8521478
Showing 1 changed file with 11 additions and 0 deletions.
diff --git 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>
@@ -1220,6 +1221,16 @@ static int synaptics_reconnect(struct psmouse *psmouse)
 
 	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);