by Henrik Rydberg

[permalink] [raw]

Subject: Re: [PATCH v4] hid-multitouch: migrate 3M PCT touch screens to hid-multitouch

On Tue, Mar 22, 2011 at 05:34:01PM +0100, Benjamin Tissoires wrote:
> This patch merges the hid-3m-pct driver into hid-multitouch.
> To keep devices working the same way they used to with hid-3m-pct,
> we need to add two signal/noise ratios for width and height.
> We also need to work on width/height to send proper
> ABS_MT_ORIENTATION flag.
>
> Importing 3M into hid-multitouch also solved the bug in which
> devices handling width and height in their report descriptors
> did not show ABS_MT_TOUCH_MAJOR and ABS_MT_TOUCH_MINOR.
>
> Signed-off-by: Benjamin Tissoires <[email protected]>
> Reviewed-by: St?phane Chatty <[email protected]>
> ---
[...]
> Henrik, do I still have your Reviewed-and-tested-by ?

Yep, looks good. One more thing, though:

> @@ -332,11 +351,18 @@ static void mt_emit_event(struct mt_device *td, struct input_dev *input)
> input_mt_report_slot_state(input, MT_TOOL_FINGER,
> s->touch_state);
> if (s->touch_state) {
> + /* this finger is on the screen */
> + int wide = (s->w > s->h);
> + /* divided by two to match visual scale of touch */
> + int major = max(s->w, s->h) >> 1;
> + int minor = min(s->w, s->h) >> 1;

This scaling is most likely not correct for all devices. I went
through a set of devices some time ago, running mtview on all of them,
visually inspecting the touch size. Some were low by a factor of two,
some were high by a factor of two. A confirmation that the other
devices supported by this driver seem right would be good. If not, a
quirk should probably be added here.

> +
> input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
> input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
> + input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
> input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
> - input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, s->w);
> - input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, s->h);
> + input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
> + input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
> }
> s->seen_in_this_frame = false;

Thanks,
Henrik

2011-03-24 11:46:19

by Jiri Kosina

[permalink] [raw]

Subject: Re: [PATCH v4] hid-multitouch: migrate 3M PCT touch screens to hid-multitouch

On Tue, 22 Mar 2011, Henrik Rydberg wrote:

> On Tue, Mar 22, 2011 at 05:34:01PM +0100, Benjamin Tissoires wrote:
> > This patch merges the hid-3m-pct driver into hid-multitouch.
> > To keep devices working the same way they used to with hid-3m-pct,
> > we need to add two signal/noise ratios for width and height.
> > We also need to work on width/height to send proper
> > ABS_MT_ORIENTATION flag.
> >
> > Importing 3M into hid-multitouch also solved the bug in which
> > devices handling width and height in their report descriptors
> > did not show ABS_MT_TOUCH_MAJOR and ABS_MT_TOUCH_MINOR.
> >
> > Signed-off-by: Benjamin Tissoires <[email protected]>
> > Reviewed-by: St?phane Chatty <[email protected]>
> > ---
> [...]
> > Henrik, do I still have your Reviewed-and-tested-by ?
>
> Yep, looks good. One more thing, though:
>
> > @@ -332,11 +351,18 @@ static void mt_emit_event(struct mt_device *td, struct input_dev *input)
> > input_mt_report_slot_state(input, MT_TOOL_FINGER,
> > s->touch_state);
> > if (s->touch_state) {
> > + /* this finger is on the screen */
> > + int wide = (s->w > s->h);
> > + /* divided by two to match visual scale of touch */
> > + int major = max(s->w, s->h) >> 1;
> > + int minor = min(s->w, s->h) >> 1;
>
> This scaling is most likely not correct for all devices. I went
> through a set of devices some time ago, running mtview on all of them,
> visually inspecting the touch size. Some were low by a factor of two,
> some were high by a factor of two. A confirmation that the other
> devices supported by this driver seem right would be good. If not, a
> quirk should probably be added here.

Okay, thanks a lot for the review. This can be handled later during
-rc phase if needed. So please proceed with confirming with the existing
devices, and meanwhile I have applied the patch.

> > +
> > input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
> > input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
> > + input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
> > input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
> > - input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, s->w);
> > - input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, s->h);
> > + input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
> > + input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
> > }
> > s->seen_in_this_frame = false;

Thanks,

--
Jiri Kosina
SUSE Labs, Novell Inc.