[PATCH v3 2/4] evdev: use a different filter for low resolution touchpad on the Lenovo X230
Vasily Khoruzhick
anarsoul at gmail.com
Thu Apr 16 12:07:30 PDT 2015
On Thu, Apr 16, 2015 at 9:41 PM, Benjamin Tissoires
<benjamin.tissoires at gmail.com> wrote:
> Those touchpads presents an actual lower resolution that what is
> advertised.
>
> We see some jumps from the cursor due to the big steps in X and Y
> when we are receiving data.
>
> For instance, we receive:
>
> E: 13.471932 0003 0000 16366 # EV_ABS / ABS_X 16366
> E: 13.471932 0003 0001 9591 # EV_ABS / ABS_Y 9591
> E: 13.471932 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
> E: 13.479924 0003 0000 16316 # EV_ABS / ABS_X 16316
> E: 13.479924 0003 0001 9491 # EV_ABS / ABS_Y 9491
> E: 13.479924 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
> E: 13.487939 0003 0000 16271 # EV_ABS / ABS_X 16271
> E: 13.487939 0003 0001 9403 # EV_ABS / ABS_Y 9403
> E: 13.487939 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
>
> -> jumps of ~50 in X in each report, and ~100 for Y.
>
> Apply a factor to minimize those jumps at low speed and try keeping
> the same feeling as regular touchpads at high speed. It still feels
> slower but it is usable at least
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires at gmail.com>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---
> Changes to v1:
> - a bit more generic than the original, makes adding new models more
> straightforward.
>
> Changes to v2:
> - changed the incline parameter to have a touchpad which feels like the other.
> Not sure these are the final parameters but they make the touchpad much
> better.
>
> doc/device-configuration-via-udev.dox | 9 ++++++++
> src/evdev-mt-touchpad.c | 14 ++++++++++--
> src/evdev.c | 23 ++++++++++++++++++++++
> src/evdev.h | 7 ++++++
> src/filter.c | 34 +++++++++++++++++++++++++++++++++
> src/filter.h | 5 ++++
> 6 files changed, 89 insertions(+), 3 deletions(-)
>
> diff --git a/doc/device-configuration-via-udev.dox b/doc/device-configuration-via-udev.dox
> index fc1c0af..c570913 100644
> --- a/doc/device-configuration-via-udev.dox
> +++ b/doc/device-configuration-via-udev.dox
> @@ -57,6 +57,15 @@ See @ref motion_normalization for details.
> <dd>The angle in degrees for each click on a mouse wheel. See
> libinput_pointer_get_axis_source() for details.
> </dd>
> +<dt>LIBINPUT_MODEL_LENOVO_X230</dt>
> +<dd><b>Do not use for anything except a Lenovo X230 series</b> (you have been
> +warned).
> +This flag allows libinput to apply a different acceleration profile for the
> +touchpads of this series of laptops to counter a hardware deficiency. It may
> +also be use to tune other parts of the inputs of these laptops, so the effects
> +of this property may change anytime and will be only tested against the
> +mentioned laptop series.
> +</dd>
> </dl>
>
> Below is an example udev rule to assign "seat1" to a device from vendor
> diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
> index 4e5a558..f88e906 100644
> --- a/src/evdev-mt-touchpad.c
> +++ b/src/evdev-mt-touchpad.c
> @@ -998,6 +998,7 @@ static int
> tp_init_accel(struct tp_dispatch *tp, double diagonal)
> {
> int res_x, res_y;
> + accel_profile_func_t profile;
>
> res_x = tp->device->abs.absinfo_x->resolution;
> res_y = tp->device->abs.absinfo_y->resolution;
> @@ -1021,9 +1022,16 @@ tp_init_accel(struct tp_dispatch *tp, double diagonal)
> tp->accel.y_scale_coeff = DEFAULT_ACCEL_NUMERATOR / diagonal;
> }
>
> - if (evdev_device_init_pointer_acceleration(
> - tp->device,
> - touchpad_accel_profile_linear) == -1)
> + switch (tp->device->model) {
> + case EVDEV_MODEL_LENOVO_X230:
> + profile = touchpad_lenovo_x230_accel_profile;
> + break;
> + default:
> + profile = touchpad_accel_profile_linear;
> + break;
> + }
> +
> + if (evdev_device_init_pointer_acceleration(tp->device, profile) == -1)
> return -1;
>
> return 0;
> diff --git a/src/evdev.c b/src/evdev.c
> index 5b4b2b6..0b705e4 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -1356,6 +1356,28 @@ evdev_read_dpi_prop(struct evdev_device *device)
> return dpi;
> }
>
> +static inline enum evdev_device_model
> +evdev_read_model(struct evdev_device *device)
> +{
> + const struct model_map {
> + const char *property;
> + enum evdev_device_model model;
> + } model_map[] = {
> + { "LIBINPUT_MODEL_LENOVO_X230", EVDEV_MODEL_LENOVO_X230 },
> + { NULL, EVDEV_MODEL_DEFAULT },
> + };
> + const struct model_map *m = model_map;
> +
> + while (m->property) {
> + if (!!udev_device_get_property_value(device->udev_device,
> + m->property))
> + break;
> + m++;
> + }
> +
> + return m->model;
> +}
> +
> /* Return 1 if the given resolutions have been set, or 0 otherwise */
> inline int
> evdev_fix_abs_resolution(struct evdev_device *device,
> @@ -1868,6 +1890,7 @@ evdev_device_create(struct libinput_seat *seat,
> device->scroll.wheel_click_angle =
> evdev_read_wheel_click_prop(device);
> device->dpi = evdev_read_dpi_prop(device);
> + device->model = evdev_read_model(device);
> /* at most 5 SYN_DROPPED log-messages per 30s */
> ratelimit_init(&device->syn_drop_limit, 30ULL * 1000, 5);
>
> diff --git a/src/evdev.h b/src/evdev.h
> index af09baa..c4bfb79 100644
> --- a/src/evdev.h
> +++ b/src/evdev.h
> @@ -63,6 +63,11 @@ enum evdev_device_tags {
> EVDEV_TAG_TOUCHPAD_TRACKPOINT = (1 << 3),
> };
>
> +enum evdev_device_model {
> + EVDEV_MODEL_DEFAULT,
> + EVDEV_MODEL_LENOVO_X230,
> +};
> +
> struct mt_slot {
> int32_t seat_slot;
> struct device_coords point;
> @@ -160,6 +165,8 @@ struct evdev_device {
>
> int dpi; /* HW resolution */
> struct ratelimit syn_drop_limit; /* ratelimit for SYN_DROPPED logging */
> +
> + enum evdev_device_model model;
> };
>
> #define EVDEV_UNHANDLED_DEVICE ((struct evdev_device *) 1)
> diff --git a/src/filter.c b/src/filter.c
> index f7ff426..8c53f22 100644
> --- a/src/filter.c
> +++ b/src/filter.c
> @@ -355,3 +355,37 @@ touchpad_accel_profile_linear(struct motion_filter *filter,
>
> return speed_out * TP_MAGIC_SLOWDOWN;
> }
> +
> +double
> +touchpad_lenovo_x230_accel_profile(struct motion_filter *filter,
> + void *data,
> + double speed_in,
> + uint64_t time)
> +{
> + /* Keep the magic factor from touchpad_accel_profile_linear. */
> + const double TP_MAGIC_SLOWDOWN = 0.4;
> +
> + /* Those touchpads presents an actual lower resolution that what is
> + * advertised. We see some jumps from the cursor due to the big steps
> + * in X and Y when we are receiving data.
> + * Apply a factor to minimize those jumps at low speed, and try
> + * keeping the same feeling as regular touchpads at high speed.
> + * It still feels slower but it is usable at least */
> + const double TP_MAGIC_LOW_RES_FACTOR = 4.0;
> + double speed_out;
> + struct pointer_accelerator *accel_filter =
> + (struct pointer_accelerator *)filter;
> +
> + const double max_accel = accel_filter->accel *
> + TP_MAGIC_LOW_RES_FACTOR; /* unitless factor */
> + const double threshold = accel_filter->threshold /
> + TP_MAGIC_LOW_RES_FACTOR; /* units/ms */
> + const double incline = accel_filter->incline * TP_MAGIC_LOW_RES_FACTOR *
> + TP_MAGIC_LOW_RES_FACTOR; /* twice the factor */
Not twice, square.
> +
> + speed_in *= TP_MAGIC_SLOWDOWN / TP_MAGIC_LOW_RES_FACTOR;
> +
> + speed_out = accel_profile_linear(speed_in, max_accel, threshold, incline);
> +
> + return speed_out * TP_MAGIC_SLOWDOWN / TP_MAGIC_LOW_RES_FACTOR;
> +}
> diff --git a/src/filter.h b/src/filter.h
> index 70363a6..a053860 100644
> --- a/src/filter.h
> +++ b/src/filter.h
> @@ -67,4 +67,9 @@ touchpad_accel_profile_linear(struct motion_filter *filter,
> void *data,
> double speed_in,
> uint64_t time);
> +double
> +touchpad_lenovo_x230_accel_profile(struct motion_filter *filter,
> + void *data,
> + double speed_in,
> + uint64_t time);
> #endif /* FILTER_H */
> --
> 1.7.1
>
> _______________________________________________
> wayland-devel mailing list
> wayland-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/wayland-devel
More information about the wayland-devel
mailing list