Re: [PATCH] driver:st1633: fixed multitouch incorrect coordinates

[Dixit Parmar]

Any review comments for this?
Or it should be merged?

Thanks.


On Thu, Aug 22, 2019 at 02:08:14PM +0200, Martin Kepplinger wrote:
> Am 19.08.2019 12:08 schrieb Dixit Parmar:
> > From: Dixit Parmar <dixitparmar19@xxxxxxxxx>
> > 
> > For Sitronix st1633 multi-touch controller driver the co-ordinates
> > reported
> > for multiple fingers were wrong.
> > 
> > So the below mentioned bug was filed,
> > Bugzilla Bug ID: 204561
> > 
> > While reading co-ordinates from specified I2C registers, the X & Y
> > co-ordinates should be read from proper I2C address for particular
> > finger as
> > specified in chip specific datasheet.
> > 
> > for single touch this logic is working fine. However, for multi-touch
> > scenario the logic of reading data from data buffer has issues.
> > 
> > This patch fixes the reading logic from data buffer.
> > 
> > Previous logic:
> > * Offset of X & Y Lower byte coordinate is increased by i no. only(by 1
> > Byte)
> >   for each finger.
> > 
> > New logic:
> > * The logic of reading X & Y Lower Byte coordinate needs to be increased
> >   by i+y for each time/finger.
> > 
> > Signed-off-by: Dixit Parmar <dixitparmar19@xxxxxxxxx>
> > ---
> >  drivers/input/touchscreen/st1232.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/input/touchscreen/st1232.c
> > b/drivers/input/touchscreen/st1232.c
> > index 3492339..1139714 100644
> > --- a/drivers/input/touchscreen/st1232.c
> > +++ b/drivers/input/touchscreen/st1232.c
> > @@ -81,8 +81,10 @@ static int st1232_ts_read_data(struct st1232_ts_data
> > *ts)
> >  	for (i = 0, y = 0; i < ts->chip_info->max_fingers; i++, y += 3) {
> >  		finger[i].is_valid = buf[i + y] >> 7;
> >  		if (finger[i].is_valid) {
> > -			finger[i].x = ((buf[i + y] & 0x0070) << 4) | buf[i + 1];
> > -			finger[i].y = ((buf[i + y] & 0x0007) << 8) | buf[i + 2];
> > +			finger[i].x = ((buf[i + y] & 0x0070) << 4) |
> > +					buf[i + y + 1];
> > +			finger[i].y = ((buf[i + y] & 0x0007) << 8) |
> > +					buf[i + y + 2];
> 
> Seems like you're right. It's simply +1 (for x) and +2 (for y) from the
> high-byte locations.
> Not sure how that went wrong.
> 
> Thank you,
> 
> Reviewed-by: Martin Kepplinger <martink@xxxxxxxxx>
> 
> 
> > 
> >  			/* st1232 includes a z-axis / touch strength */
> >  			if (ts->chip_info->have_z)
>