Re: [PATCH] input: goodix: Check the 'data ready' bit before reading data

[paul]

Hi Bastien,

Ok, I will send a V2 with a better commit message then.

-Paul

Le 2015-04-25 14:54, Bastien Nocera a ÃcritÂ:
> On Sat, 2015-04-25 at 12:48 +0200, Paul Cercueil wrote:
> > The MSB of the first byte read via I2C seems to indicate whether the
> > data is valid (or ready) when an interrupt is raised. Previously,
> > this
> > bit was ignored, which resulted in a lot of incorrect detections of
> > "finger removed" events.
>
> This seems correct, but the wording doesn't match the language used in
> the Goodix docs that were posted here some time ago[1].
>
> I would have written:
> The MSB of the first byte read via I2C at the coordinates address
> indicate whether the data is valid or ready (called "buffer status" in
> the datasheets) when an interrupt is raised. Previously, this bit was
> ignored, which resulted in a lot of incorrect detections of "finger
> removed" events.
>
> And for the commit subject:
> input: goodix: Check the 'buffer status' bit before reading data
>
> This seems correct otherwise.
>
> Signed-off-by: Bastien Nocera <hadess@xxxxxxxxxx>
>
> with the fixed commit message/subject
>
> [1]: Linked from the device tree support patch:
> https://patchwork.ozlabs.org/patch/446838/
> Page 16, table c, 0x814E is what we read for coordinates
>
> > Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> > ---
> >  drivers/input/touchscreen/goodix.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/input/touchscreen/goodix.c
> > b/drivers/input/touchscreen/goodix.c
> > index ca19668..9fa6c5f 100644
> > --- a/drivers/input/touchscreen/goodix.c
> > +++ b/drivers/input/touchscreen/goodix.c
> > @@ -98,6 +98,9 @@ static int goodix_ts_read_input_report(struct
> > goodix_ts_data *ts, u8 *data)
> >               return error;
> >       }
> >
> > +     if (!(data[0] & 0x80))
> > +             return -EAGAIN;
> > +
> >       touch_num = data[0] & 0x0f;
> >       if (touch_num > GOODIX_MAX_CONTACTS)
> >               return -EPROTO;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/