RE: [PATCH 2/9] input: goodix: fix variable length array warning

Tirdea, Irina
2015-06-03T10:27:04Z

> -----Original Message-----
> From: Antonio Ospite [mailto:ao2@ao2.it]
> Sent: 28 May, 2015 18:58
> To: Tirdea, Irina
> Cc: Dmitry Torokhov; Bastien Nocera; linux-input@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 2/9] input: goodix: fix variable length array warning
>
> On Thu, 28 May 2015 15:47:38 +0300
> Irina Tirdea <irina.tirdea@intel.com> wrote:
>
> > Fix sparse warning:
> > drivers/input/touchscreen/goodix.c:182:26: warning:
> > Variable length array is used.
> >
> > Replace the variable length array with fixed length.
> >
> > Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
> > ---
> > drivers/input/touchscreen/goodix.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> > index c2e785c..dac1b3c 100644
> > --- a/drivers/input/touchscreen/goodix.c
> > +++ b/drivers/input/touchscreen/goodix.c
> > @@ -147,7 +147,7 @@ static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
> > */
> > static void goodix_process_events(struct goodix_ts_data *ts)
> > {
> > - u8 point_data[1 + GOODIX_CONTACT_SIZE * ts->max_touch_num];
> > + u8 point_data[1 + GOODIX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
>
> Hi,
>

Hi Antonio,

> this fixes the warning from sparse, but also changes the semantics of
> the code: ts->max_touch_num is less that GOODIX_MAX_CONTACTS for 5
> touches devices and in this case we'll end up using more memory than is
> necessary.
>

I wasn't sure if it is better to save the 5 bytes or fix the warning, so I sent this to get some more input.
Thanks for the feedback, I will drop this patch.

Thanks,
Irina

> Thanks,
> Antonio
>
> > int touch_num;
> > int i;
> >
> > --
> > 1.9.1
> >
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> --
> Antonio Ospite
> http://ao2.it
>
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