On Saturday 05 November 2016 17:44:58 Paul Donohue wrote:
> The current Alps SS5 (SS4 v2) code generates bogus TouchPad events when
> TrackStick packets are processed.
>
> This causes the xorg synaptics driver to print
> "unable to find touch point 0" and
> "BUG: triggered 'if (priv->num_active_touches > priv->num_slots)'"
> messages. It also causes unexpected TouchPad button release and reclick
> event sequences if the TrackStick is moved while holding a TouchPad
> button.
>
> This commit corrects the problem by adjusting
> alps_process_packet_ss4_v2() so that it only sends TrackStick reports
> when processing TrackStick packets.
>
> Signed-off-by: Paul Donohue <linux-kernel@xxxxxxxxxx>
>
> diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
> index 6d7de9b..1d0302b 100644
> --- a/drivers/input/mouse/alps.c
> +++ b/drivers/input/mouse/alps.c
> @@ -1279,6 +1279,8 @@ static int alps_decode_ss4_v2(struct alps_fields *f,
> input_report_rel(priv->dev2, REL_Y, -y);
> input_report_abs(priv->dev2, ABS_PRESSURE, pressure);
> }
> + f->first_mp = 0;
> + f->is_mp = 0;
> break;
>
> case SS4_PACKET_ID_IDLE:
> @@ -1346,18 +1348,18 @@ static void alps_process_packet_ss4_v2(struct psmouse *psmouse)
>
> priv->multi_packet = 0;
>
> - alps_report_mt_data(psmouse, (f->fingers <= 4) ? f->fingers : 4);
> + if ((packet[3] & 0x30) != 0x20) {
Ideally adds comment that this is test for SS4_PACKET_ID_STICK.
> + alps_report_mt_data(psmouse, (f->fingers <= 4) ? f->fingers : 4);
>
> - input_mt_report_finger_count(dev, f->fingers);
> + input_mt_report_finger_count(dev, f->fingers);
>
> - input_report_key(dev, BTN_LEFT, f->left);
> - input_report_key(dev, BTN_RIGHT, f->right);
> - input_report_key(dev, BTN_MIDDLE, f->middle);
> + input_report_key(dev, BTN_LEFT, f->left);
> + input_report_key(dev, BTN_RIGHT, f->right);
> + input_report_key(dev, BTN_MIDDLE, f->middle);
>
> - input_report_abs(dev, ABS_PRESSURE, f->pressure);
> - input_sync(dev);
> -
> - if (priv->flags & ALPS_DUALPOINT) {
> + input_report_abs(dev, ABS_PRESSURE, f->pressure);
> + input_sync(dev);
> + } else if (priv->flags & ALPS_DUALPOINT) {
> input_report_key(dev2, BTN_LEFT, f->ts_left);
> input_report_key(dev2, BTN_RIGHT, f->ts_right);
> input_report_key(dev2, BTN_MIDDLE, f->ts_middle);
>
Otherwise this patch looks OK.
Anyway, I looked into alps.c source code and I see there another
problem with ss4 devices. Function alps_decode_ss4_v2() calls
input_report_*() functions without input_sync(). But all those
input_report_*() should be in alps_process_packet_ss4_v2().
Would you like to fix this problem?
I think due to this problem, original code contains that BUG reported
by you...
--
Pali Rohár
pali.rohar@xxxxxxxxx
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