From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaswinder Singh Rajput Subject: Re: [PATCH] Input: bcm5974.c initialize raw_w, raw_x and raw_y before it get used Date: Sun, 13 Sep 2009 14:01:30 +0530 Message-ID: <1252830690.3440.5.camel@ht.satnam> References: <1252775770.3687.7.camel@ht.satnam> <4AAC2DBE.9040303@bitmath.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from hera.kernel.org ([140.211.167.34]:59478 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751186AbZIMIcK (ORCPT ); Sun, 13 Sep 2009 04:32:10 -0400 In-Reply-To: <4AAC2DBE.9040303@bitmath.org> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Henrik Rydberg Cc: Dmitry Torokhov , linux-input@vger.kernel.org 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 >=20 > Thanks for the heads up, but actually not, since !raw_n also implies > !(ptest > PRESSURE_LOW). >=20 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 : > >=20 > > CC [M] drivers/input/mouse/bcm5974.o > > drivers/input/mouse/bcm5974.c: In function =E2=80=98report_tp_state= =E2=80=99: > > drivers/input/mouse/bcm5974.c:319: warning: =E2=80=98raw_y=E2=80=99= may be used uninitialized in this function > > drivers/input/mouse/bcm5974.c:319: warning: =E2=80=98raw_x=E2=80=99= may be used uninitialized in this function > > drivers/input/mouse/bcm5974.c:319: warning: =E2=80=98raw_w=E2=80=99= may be used uninitialized in this function > >=20 > > Signed-off-by: Jaswinder Singh Rajput > > --- > > drivers/input/mouse/bcm5974.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > >=20 > > diff --git a/drivers/input/mouse/bcm5974.c b/drivers/input/mouse/bc= m5974.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 =3D=3D TYPE2) > > ibt =3D raw2int(dev->tp_data[BUTTON_TYPE2]); > > - } > > + } else > > + raw_w =3D raw_x =3D raw_y =3D 0; > > =20 > > /* while tracking finger still valid, count all fingers */ > > if (ptest > PRESSURE_LOW && origin) { >=20 > I would prefer treating raw_p on the same footing here, completing th= e set of > non-obviously initialized variables. It might also make sense to util= ize the > same initialization technique already used in the code, thus: >=20 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/bcm5= 974.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, i= nt size) > const struct bcm5974_config *c =3D &dev->cfg; > const struct tp_finger *f; > struct input_dev *input =3D dev->input; > - int raw_p, raw_w, raw_x, raw_y, raw_n; > + int raw_p =3D 0, raw_w =3D 0, raw_x =3D 0, raw_y =3D 0, raw_n; > int ptest =3D 0, origin =3D 0, ibt =3D 0, nmin =3D 0, nmax =3D 0; > int abs_p =3D 0, abs_w =3D 0, abs_x =3D 0, abs_y =3D 0; >=20 >=20 > I wonder how many cpu cycles in the world are spent making compilers = happy. >=20 It is not compiler mistake it is programming/logic mistakes. We should be thankful to compiler to pointing mistakes made by us. Thanks, -- JSR -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html