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

[Tirdea, Irina]

> -----Original Message-----
> From: Antonio Ospite [mailto:ao2@xxxxxx]
> Sent: 28 May, 2015 18:58
> To: Tirdea, Irina
> Cc: Dmitry Torokhov; Bastien Nocera; linux-input@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> 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@xxxxxxxxx> 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@xxxxxxxxx>
> > ---
> >  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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