Hi Hans:

-----Original Message-----
From: linux-input-owner@vger.kernel.org

[mailto:linux-input-owner@vger.kernel.org]

On Behalf Of Hans de Goede
Sent: Tuesday, December 10, 2013 4:46 PM
To: duson; 'Dmitry Torokhov'; 'Benjamin Tissoires'
Cc: 'linux-input'; 'Peter Hutterer'; '黃世鵬'
Subject: Re: [PATCH 1/2] elantech: Properly differentiate between

clickpads and

normal touchpads

Hi Duson,

On 12/10/2013 09:35 AM, duson wrote:

<snip>

quoted

quoted

We should not advertise events that device does not generate. This
should help userspace to decide if emulation is needed or not. Input
core will drop events that are not set up as valid for device, so if we
clear BTN_RIGHT there it should all work.

Actually, our touchpad for PS2 protocol implements the left and right

click

quoted

function, even thought, it is a click-pad. And the flag for left/right

click

quoted

information is recorded in the first byte of the packet (when doing sync
method).
	Byte0 Bit 0 --> for left click flag
	Byte0 Bit1 --> for right click flag
When user presses the left-bottom area of the click-pad, only the left

click

quoted

flag will be set to "1". On the other hand, pressing the right-bottom

area

quoted

of the click-pad, only the right click flag will be set to "1".
So, I think this is the cause of the BTN_RIGHT need to be set.

Are you sure? All info we have so far indicates that the right button

needs

to be emulated in software in the clickpad case, ie a while back this
commit was added:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drive
rs/input/mous

e/elantech.c?id=e3dde4fba94e0ba5e1fd79ea9e5389eea1f0cfec

To fix the right button not working, this also removes the checking
for bit 1 / reporting of BTN_RIGHT events, so if the right click area
would actually send right clicks I would expect the above commit to
have broken right clicking for tons of users, and we have no bug reports
about this (my patch fixes the right button being broken in the non
clickpad case).

Note that the Linux driver uses the touchpad in absolute mode, not in
relative / ps/2 mouse emulation mode. Could it be that the handling of the
right button emulation for clickpads is only done in the firmware in
relative mode ?

Or maybe it is done in firmware for hardware v3 clickpads, but not for
v4 clickpads ?

Sorry, this is my mistake. I had confirmed our firmware engineer again.
The correct answer is "When using click-pad in absolute mode only the left
click function work." So, both the left/right click function is enabled when
using normal smart-pad (non-clickpad) or clickpad in relative mode.

Thanks,
Duson

--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html