[PATCH 2/4] Input - synaptics: do not release extra buttons once they are pressed

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

The current code releases the extra buttons right after they are pressed.
As soon as a new serio report comes in, the hw state is reset to 0
and so the buttons are released.

Check for the report type before acting on the current extra buttons
state.

Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
 drivers/input/mouse/synaptics.c | 10 +++++++---
 drivers/input/mouse/synaptics.h |  3 +++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index 0d12664..d58863b 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -688,7 +688,7 @@ static int synaptics_parse_hw_state(const unsigned char buf[],
 		}
 
 		if (SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap) &&
-		    ((buf[0] ^ buf[3]) & 0x02)) {
+		    SYN_REPORT_EXT_BUTTONS(buf)) {
 			switch (SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap)) {
 			default:
 				/*
@@ -792,8 +792,12 @@ static void synaptics_report_buttons(struct psmouse *psmouse,
 		input_report_key(dev, BTN_BACK, hw->down);
 	}
 
-	for (i = 0; i < SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap); i++)
-		input_report_key(dev, BTN_0 + i, hw->ext_buttons & (1 << i));
+	if (SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap) &&
+	    SYN_REPORT_EXT_BUTTONS(psmouse->packet)) {
+		for (i = 0; i < SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap); i++)
+			input_report_key(dev, BTN_0 + i,
+					 hw->ext_buttons & (1 << i));
+	}
 }
 
 static void synaptics_report_mt_data(struct psmouse *psmouse,
diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
index 6faf9bb..0b2b711 100644
--- a/drivers/input/mouse/synaptics.h
+++ b/drivers/input/mouse/synaptics.h
@@ -115,6 +115,9 @@
 #define SYN_NEWABS_RELAXED		2
 #define SYN_OLDABS			3
 
+/* synaptics extended button packet */
+#define SYN_REPORT_EXT_BUTTONS(buf)	(((buf)[0] ^ (buf)[3]) & 0x02)
+
 /* amount to fuzz position data when touchpad reports reduced filtering */
 #define SYN_REDUCED_FILTER_FUZZ		8
 
-- 
2.1.0