On Sun, 2009-09-13 at 01:24 +0200, Henrik Rydberg wrote:
> Jaswinder Singh Rajput wrote:
> > raw_w, raw_x and raw_y is used uninitialized for !raw_n
>
> Thanks for the heads up, but actually not, since !raw_n also implies
> !(ptest > PRESSURE_LOW).
>
Then can we move 'if (ptest > PRESSURE_LOW && origin)' stuff to 'if
(raw_n)'. If not then my patch is correct.
> > This also fixed these compilation warnings :
> >
> > CC [M] drivers/input/mouse/bcm5974.o
> > drivers/input/mouse/bcm5974.c: In function ‘report_tp_state’:
> > drivers/input/mouse/bcm5974.c:319: warning: ‘raw_y’ may be used uninitialized in this function
> > drivers/input/mouse/bcm5974.c:319: warning: ‘raw_x’ may be used uninitialized in this function
> > drivers/input/mouse/bcm5974.c:319: warning: ‘raw_w’ may be used uninitialized in this function
> >
> > Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@xxxxxxxxx>
> > ---
> > drivers/input/mouse/bcm5974.c | 3 ++-
> > 1 files changed, 2 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/input/mouse/bcm5974.c b/drivers/input/mouse/bcm5974.c
> > index 2d8fc0b..171f345 100644
> > --- a/drivers/input/mouse/bcm5974.c
> > +++ b/drivers/input/mouse/bcm5974.c
> > @@ -345,7 +345,8 @@ static int report_tp_state(struct bcm5974 *dev, int size)
> > /* set the integrated button if applicable */
> > if (c->tp_type == TYPE2)
> > ibt = raw2int(dev->tp_data[BUTTON_TYPE2]);
> > - }
> > + } else
> > + raw_w = raw_x = raw_y = 0;
> >
> > /* while tracking finger still valid, count all fingers */
> > if (ptest > PRESSURE_LOW && origin) {
>
> I would prefer treating raw_p on the same footing here, completing the set of
> non-obviously initialized variables. It might also make sense to utilize the
> same initialization technique already used in the code, thus:
>
No, then you are wasting cpu cycles and doing double initialization for
some cases.
> diff --git a/drivers/input/mouse/bcm5974.c b/drivers/input/mouse/bcm5974.c
> index 2d8fc0b..2f85876 100644
> --- a/drivers/input/mouse/bcm5974.c
> +++ b/drivers/input/mouse/bcm5974.c
> @@ -316,7 +316,7 @@ static int report_tp_state(struct bcm5974 *dev, int size)
> const struct bcm5974_config *c = &dev->cfg;
> const struct tp_finger *f;
> struct input_dev *input = dev->input;
> - int raw_p, raw_w, raw_x, raw_y, raw_n;
> + int raw_p = 0, raw_w = 0, raw_x = 0, raw_y = 0, raw_n;
> int ptest = 0, origin = 0, ibt = 0, nmin = 0, nmax = 0;
> int abs_p = 0, abs_w = 0, abs_x = 0, abs_y = 0;
>
>
> I wonder how many cpu cycles in the world are spent making compilers happy.
>
It is not compiler mistake it is programming/logic mistakes. We should
be thankful to compiler to pointing mistakes made by us.
Thanks,
--
JSR
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