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

On Mon, Feb 2, 2015 at 4:46 PM, Dmitry Torokhov
[off-list ref] wrote:

On Wed, Jan 28, 2015 at 03:10:05PM -0500, Benjamin Tissoires wrote:

quoted

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.

No:

"If Ext is 0 (if bit 1 of bytes 1 and 4 are the same) then there are no
external buttons being pressed (or all external buttons have been
released)." - Synaptics PS/2 TouchPad Interfacing Guide PN:
511-000275-01 Rev. B

Hmm, indeed, the current code follows the spec. Yeah! a new firmware bug!

So when I dumped the ps/2 reports, I clearly saw the release report
being sent with the Ext bit to 1, and other reports were in between
with no information (because no fingers were on the touchpad).

I may have access to the hardware tomorrow if the snow has been
removed from the roads, but tonight, I won't be able to test anything
:(

Cheers,
Benjamin

quoted

Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <redacted>
---
 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

--
Dmitry
--
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