Re: [PATCH] made the byd_detect function more restrictive to prevent false positives when actual mouse is a generic PS/2 mouse; byd_detect now tries to go through BYD touchpad configuration steps, which fail when not performed on BYD touchpad

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Richard,

On Sat, Jun 25, 2016 at 07:25:21PM -0700, Richard Pospesel wrote:
> ---
>  drivers/input/mouse/byd.c | 21 ++++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
> index ec73f75..380e295 100644
> --- a/drivers/input/mouse/byd.c
> +++ b/drivers/input/mouse/byd.c
> @@ -355,7 +355,7 @@ static int byd_reset_touchpad(struct psmouse *psmouse)
>  		{ PSMOUSE_CMD_ENABLE, 0 },
>  		/*
>  		 * BYD-specific initialization, which enables absolute mode and
> -		 * (if desired), the touchpad's built-in gesture detection.
> +		 * disables the builtin hardware gesture recogniton.
>  		 */
>  		{ 0x10E2, 0x00 },
>  		{ 0x10E0, 0x02 },
> @@ -435,6 +435,7 @@ int byd_detect(struct psmouse *psmouse, bool set_properties)
>  	struct ps2dev *ps2dev = &psmouse->ps2dev;
>  	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
>  
> +	/* 'Secret' handshake */
>  	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>  		return -1;
>  	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> @@ -446,7 +447,21 @@ int byd_detect(struct psmouse *psmouse, bool set_properties)
>  	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
>  		return -1;
>  
> -	if (param[1] != 0x03 || param[2] != 0x64)
> +	/*
> +	 * BYD touchpad returns 0x03 for resolution ( 8 count / mm ) and
> +	 * 0x64 ( 100 samples / sec ) for sampling rate
> +	 * The first byte's value is dependent on the mouse button states:
> +	 *  0 : no button pressed
> +	 *  1 : right button pressed
> +	 *  4 : left button pressed
> +	 *  5 : right and left button pressed
> +	 */
> +	if ((param[0] & 0x05) != param[0] || param[1] != 0x03 ||
> +	    param[2] != 0x64)
> +		return -ENODEV;
> +
> +	/* Attempt to set BYD unique settings */
> +	if (byd_reset_touchpad(psmouse))
>  		return -ENODEV;

If we do full initialization then there is no point in splitting into
byd_detect/byd_init and repeating initialization in byd_init() and
byd_reconnect().

Thanks.

-- 
Dmitry