Re: [PATCH] Input: synaptics-rmi4 - Do not set reduced reporting mode thresholds are not set by the driver

From: Peter Hutterer
Date: Wed Mar 11 2020 - 23:14:34 EST


Hi Andrew,

On Wed, Mar 11, 2020 at 05:55:49PM -0700, Andrew Duggan wrote:
> The previous patch "c5ccf2ad3d33 (Input: synaptics-rmi4 - switch to
> reduced reporting mode)" enabled reduced reporting mode unintentionally
> on some devices, if the firmware was configured with default Delta X/Y
> threshold values. The result unintentionally degrade the performance of
> some touchpads.

could this be the cause of a stuttering cursor on a P50 as well?
A recording in the issue below shows the cursor moving by ~25 units per
event, regardless of the time between those events.
https://gitlab.freedesktop.org/libinput/libinput/issues/448

thanks!

Cheers,
Peter

> This patch checks to see that the driver is modifying the delta X/Y
> thresholds before modifying the reporting mode.
>
> Signed-off-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
> ---
> drivers/input/rmi4/rmi_f11.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/rmi4/rmi_f11.c b/drivers/input/rmi4/rmi_f11.c
> index 6adea8a3e8fb..ffa39ab153f2 100644
> --- a/drivers/input/rmi4/rmi_f11.c
> +++ b/drivers/input/rmi4/rmi_f11.c
> @@ -1203,8 +1203,8 @@ static int rmi_f11_initialize(struct rmi_function *fn)
> * If distance threshold values are set, switch to reduced reporting
> * mode so they actually get used by the controller.
> */
> - if (ctrl->ctrl0_11[RMI_F11_DELTA_X_THRESHOLD] ||
> - ctrl->ctrl0_11[RMI_F11_DELTA_Y_THRESHOLD]) {
> + if (sensor->axis_align.delta_x_threshold ||
> + sensor->axis_align.delta_y_threshold) {
> ctrl->ctrl0_11[0] &= ~RMI_F11_REPORT_MODE_MASK;
> ctrl->ctrl0_11[0] |= RMI_F11_REPORT_MODE_REDUCED;
> }
> --
> 2.20.1
>