Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753715AbbLCUeD (ORCPT ); Thu, 3 Dec 2015 15:34:03 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:34721 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753386AbbLCUeA (ORCPT ); Thu, 3 Dec 2015 15:34:00 -0500 Date: Thu, 3 Dec 2015 12:33:57 -0800 From: Brian Norris To: Dmitry Torokhov Cc: Caesar Wang , Eduardo Valentin , huangtao@rock-chips.com, Heiko Stuebner , dianders@chromium.org, linux-rockchip@lists.infradead.org, Dan Carpenter , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Zhang Rui , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 2/5] thermal: rockchip: fix a impossible condition caused by the warning Message-ID: <20151203203357.GA141945@google.com> References: <1449132523-18817-1-git-send-email-wxt@rock-chips.com> <1449132523-18817-3-git-send-email-wxt@rock-chips.com> <20151203201908.GA34901@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151203201908.GA34901@dtor-ws> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2459 Lines: 69 On Thu, Dec 03, 2015 at 12:19:08PM -0800, Dmitry Torokhov wrote: > On Thu, Dec 03, 2015 at 04:48:40PM +0800, Caesar Wang wrote: > > As the Dan report the smatch check the thermal driver warning: > > drivers/thermal/rockchip_thermal.c:551 rockchip_configure_from_dt() > > warn: impossible condition '(thermal->tshut_temp > ((~0 >> 1))) => > > (s32min-s32max > s32max)' > > > > Let's we remove the imposssible condition Since the Temperature is > > currently represented as int not long in the thermal driver. > > > > Fixes: commit 437df2172e8d > > ("thermal: rockchip: consistently use int for temperatures") > > > > Reported-by: Dan Carpenter > > Signed-off-by: Caesar Wang > > > > --- > > > > Changes in v3: > > - As Brian comments on https://patchwork.kernel.org/patch/7580661/, > > let's remove the impossible condition. > > > > Changes in v2: None > > Changes in v1: None > > > > drivers/thermal/rockchip_thermal.c | 6 ------ > > 1 file changed, 6 deletions(-) > > > > diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c > > index ae796ec..611de00 100644 > > --- a/drivers/thermal/rockchip_thermal.c > > +++ b/drivers/thermal/rockchip_thermal.c > > @@ -549,12 +549,6 @@ static int rockchip_configure_from_dt(struct device *dev, > > thermal->tshut_temp = shut_temp; > > } > > > > - if (thermal->tshut_temp > INT_MAX) { > > - dev_err(dev, "Invalid tshut temperature specified: %d\n", > > - thermal->tshut_temp); > > - return -ERANGE; > > - } > > Well, that is not entirely correct. The value that we read from DT is > u32, but we convert it down to int. I believe you want to move the check Do we really account for the possibility of sizeof(int) < sizeof(u32)? EDIT: A bit after writing the above line, I notice my error, but in case anyone else is thinking the same thing... I guess you're referring to the sign bit, since we're casting unsigned to signed. Brian > up so that you do: > > } else if (tshut_temp > INT_MAX) { > dev_err(dev, "Invalid tshut temperature specified: %d\n", > thermal->tshut_temp); > return -ERANGE; > } else { > thermal->tshut_temp = shut_temp; > } > > Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/