linux-kernel - Re: synaptics touchpad doesn't click

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 15 Dec 2009 07:40:55 +0100
From:	Takashi Iwai <tiwai@...e.de>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:	Alex Chiang <achiang@...com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-input@...r.kernel.org
Subject: Re: synaptics touchpad doesn't click

At Mon, 14 Dec 2009 22:26:28 -0800,
Dmitry Torokhov wrote:
> 
> [1  <text/plain; us-ascii (7bit)>]
> Hi Alex,
> 
> On Mon, Dec 14, 2009 at 08:41:27PM -0700, Alex Chiang wrote:
> > 
> > Thanks, I did grab Takashi's patches and verify that they work
> > for me. I tested the separated patches, not the v2 combined
> > patch, although it doesn't make any difference based on visual
> > inspection of v2.
> > 
> > If you want, you can add my:
> > 
> > Tested-by: Alex Chiang <achiang@...com>
> 
> Thank you very much for testing, however could you please try a slightly
> different patch below (I did not quite like that the original patch
> mangled device's capability field and how it was reusing 'middle' field
> for different things)? It should apply on top of patch that
> I am attaching. I hope I did not screw it up too much,

I can't test the patch right now since I'm at home, but I'm afraid
it's a bit different behavior.  Namely,

> @@ -330,20 +339,52 @@ static void synaptics_parse_new_hw(unsigned char buf[],
>  				   struct synaptics_data *priv,
>  				   struct synaptics_hw_state *hw)
>  {
> -	hw->x = (((buf[3] & 0x10) << 8) | ((buf[1] & 0x0f) << 8) | buf[4]);
> -	hw->y = (((buf[3] & 0x20) << 7) | ((buf[1] & 0xf0) << 4) | buf[5]);
> +	int x = (((buf[3] & 0x10) << 8) | ((buf[1] & 0x0f) << 8) | buf[4]);
> +	int y = (((buf[3] & 0x20) << 7) | ((buf[1] & 0xf0) << 4) | buf[5]);
>  
>  	hw->z = buf[2];
>  	hw->w = (((buf[0] & 0x30) >> 2) |
>  		 ((buf[0] & 0x04) >> 1) |
>  		 ((buf[3] & 0x04) >> 2));
>  
> -	hw->left  = buf[0] & 0x01;
> -	hw->right = buf[0] & 0x02;
> +	if (SYN_CAP_CLICKPAD(priv->ext_cap)) {
> +		int click = (buf[0] ^ buf[3]) & 0x01;
> +
> +		if (click && y < YMIN_NOMINAL) {
> +			/*
> +			 * User pressed in ClickZone; report new button
> +			 * state but use old coordinates and don't report
> +			 * any pressure to prevent pointer movement.
> +			 */
> +			hw->left = x < CLICKPAD_LEFT_BTN_X;
> +			hw->right = x > CLICKPAD_RIGHT_BTN_X;
> +			hw->middle = x >= CLICKPAD_LEFT_BTN_X &&
> +				     x <= CLICKPAD_RIGHT_BTN_X;
> +			hw->z = 0;
> +
> +		} else {
> +			/*
> +			 * Finger is outside of the ClickZone - report
> +			 * current coordinates.
> +			 */
> +			hw->x = x;
> +			hw->y = y;
> +
> +			if (!click)
> +				hw->left = hw->right = hw->middle = 0;
> +		}

Here, when you touch outside the button area, left/right/middle are
always zero because hw was initialized.  So the above code gives the
click "released" state outside the button area.

In my original patch, the button states are kept.  This makes the
second touch while pressing the pad as dragging.  Since the button
choice is done by the first touch, you can't determine the button
position by the current touch.  Thus, remembering the last button
states is mandatory for ClickZone mode.


thanks,

Takashi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/