Re: [PATCH 06/12] Input: synaptics - fuzz position if touchpad reports reduced filtering

Chase Douglas
2011-07-05T17:50:06Z

On 06/28/2011 10:07 PM, djkurtz@chromium.org wrote:
> From: Daniel Kurtz <djkurtz@chromium.org>
>
> Synaptics touchpads indicate via a capability bit when they perform
> reduced filtering on position data.
> In such a case, use a non-zero fuzz value.
> Fuzz = 8 was chosen empirically by observing the raw position data
> reported by a clickpad indicating it had reduced filtering.
>
> Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>

Seems reasonable to me.

Acked-by: Chase Douglas <chase.douglas@canonical.com>

> ---
> drivers/input/mouse/synaptics.c | 17 ++++++++++-------
> drivers/input/mouse/synaptics.h | 3 +++
> 2 files changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
> index 74b1222..dc54675 100644
> --- a/drivers/input/mouse/synaptics.c
> +++ b/drivers/input/mouse/synaptics.c
> @@ -687,23 +687,27 @@ static psmouse_ret_t synaptics_process_byte(struct psmouse *psmouse)
> static void set_input_params(struct input_dev *dev, struct synaptics_data *priv)
> {
> int i;
> + int fuzz = 0;
>
> __set_bit(INPUT_PROP_POINTER, dev->propbit);
>
> + if (SYN_CAP_REDUCED_FILTERING(priv->ext_cap_0c))
> + fuzz = SYN_REDUCED_FILTER_FUZZ;
> +
> __set_bit(EV_ABS, dev->evbit);
> - input_set_abs_params(dev, ABS_X,
> - XMIN_NOMINAL, priv->x_max ?: XMAX_NOMINAL, 0, 0);
> - input_set_abs_params(dev, ABS_Y,
> - YMIN_NOMINAL, priv->y_max ?: YMAX_NOMINAL, 0, 0);
> + input_set_abs_params(dev, ABS_X, XMIN_NOMINAL,
> + priv->x_max ?: XMAX_NOMINAL, fuzz, 0);
> + input_set_abs_params(dev, ABS_Y, YMIN_NOMINAL,
> + priv->y_max ?: YMAX_NOMINAL, fuzz, 0);
> input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);
>
> if (SYN_CAP_ADV_GESTURE(priv->ext_cap_0c)) {
> __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
> input_mt_init_slots(dev, 2);
> input_set_abs_params(dev, ABS_MT_POSITION_X, XMIN_NOMINAL,
> - priv->x_max ?: XMAX_NOMINAL, 0, 0);
> + priv->x_max ?: XMAX_NOMINAL, fuzz, 0);
> input_set_abs_params(dev, ABS_MT_POSITION_Y, YMIN_NOMINAL,
> - priv->y_max ?: YMAX_NOMINAL, 0, 0);
> + priv->y_max ?: YMAX_NOMINAL, fuzz, 0);
>
> input_abs_set_res(dev, ABS_MT_POSITION_X, priv->x_res);
> input_abs_set_res(dev, ABS_MT_POSITION_Y, priv->y_res);
> @@ -977,4 +981,3 @@ bool synaptics_supported(void)
> }
>
> #endif /* CONFIG_MOUSE_PS2_SYNAPTICS */
> -
> diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
> index 34bedde..8a68e66 100644
> --- a/drivers/input/mouse/synaptics.h
> +++ b/drivers/input/mouse/synaptics.h
> @@ -110,6 +110,9 @@
> #define SYN_NEWABS_RELAXED 2
> #define SYN_OLDABS 3
>
> +/* amount to fuzz position data when touchpad reports reduced filtering */
> +#define SYN_REDUCED_FILTER_FUZZ 8
> +
> /*
> * A structure to describe the state of the touchpad hardware (buttons and pad)
> */