Re: [PATCH 2/2] input: synaptics - fix width calculation on image sensors

From: Benjamin Tissoires
Date: Mon Jan 05 2015 - 13:42:19 EST


On Mon, Jan 5, 2015 at 1:37 PM, Gabriele Mazzotta
<gabriele.mzt@xxxxxxxxx> wrote:
> On Monday 05 January 2015 13:25:38 Benjamin Tissoires wrote:
>> Hi Gabriele,
>>
>> On Sat, Dec 27, 2014 at 6:31 AM, Gabriele Mazzotta
>> <gabriele.mzt@xxxxxxxxx> wrote:
>> > When two or more fingers are on the touchpad, the 'w' slot holds the
>> > finger count rather than the width. Retrieve the correct value encoded
>> > in the lower bits of 'x', 'y' and 'z'.
>> >
>> > The minimum width reported is 8 rather than 4 in this case, while the
>> > maximum remains 15.
>> >
>> > Signed-off-by: Gabriele Mazzotta <gabriele.mzt@xxxxxxxxx>
>> > ---
>> > drivers/input/mouse/synaptics.c | 4 +++-
>> > 1 file changed, 3 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
>> > index ea0563e..5ff4c5b 100644
>> > --- a/drivers/input/mouse/synaptics.c
>> > +++ b/drivers/input/mouse/synaptics.c
>> > @@ -593,7 +593,9 @@ static void synaptics_parse_agm(const unsigned char buf[],
>> > switch (agm_packet_type) {
>> > case 1:
>> > /* Gesture packet: (x, y, z) half resolution */
>> > - agm->w = hw->w;
>> > + agm->w = ((buf[1] & 0x01) |
>> > + ((buf[2] & 0x01) << 1) |
>> > + ((buf[5] & 0x01) << 2)) + 8;
>> > agm->x = (((buf[4] & 0x0f) << 8) | buf[1]) << 1;
>>
>> For completeness, I think, we should also removes the w bits from x, y
>> and z (by masking buf[1], buf[2] and buf[5] with 0xfe).
>
> You are right, I forgot about it.
>
> I was going to re-submit these patches anyway since there have been
> quite a few changes and these can no longer be applied on next.

OK, I am trying to put together my thoughts for 1/2 right now. If you
could just wait a little before resubmitting, I would be grateful.

Thanks,
Benjamin

>
>> Cheers,
>> Benjamin
>>
>> > agm->y = (((buf[4] & 0xf0) << 4) | buf[2]) << 1;
>> > agm->z = ((buf[3] & 0x30) | (buf[5] & 0x0f)) << 1;
>> > --
>> > 2.1.4
>> >
>> > --
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