From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F09361BC5C; Sun, 6 Oct 2024 14:25:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728224743; cv=none; b=qRlwwLX+AAo7JKx/opEKgMzo4anq15X0Cew8uTKpKgS+cKhQcC40UkQ9rUpXINnqsBzXFklIKPRpWiPTGTvZbftW7PNbxx8MiXftX2CDatPn8RHvhPBw6iHG9ZxjYhLodUFoQtznkBB+Acb2UhnChn+g92eNtFxhKOaMCQVCryw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728224743; c=relaxed/simple; bh=VkvN3Ikd1Kd8c5idpilxjQqs75DVPd/LG7krmaFwONU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=BcpgJR5/SjC4FRD/UARp2G9vTWZUmLzJTMtYDUrBtVQpcD5EHFhFkirXC8clgENmYb7uhm30gW2Iwj5J18GAEPF+kKwO/DwY1fiudR7YxzsQnNWBo4+Da0w8dOhR9gNgm624ODS0AO6iv3r02WO86c0zcLbOY/90aeAhHPz+c5k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OYE/baFK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OYE/baFK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E94E8C4CEC5; Sun, 6 Oct 2024 14:25:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728224742; bh=VkvN3Ikd1Kd8c5idpilxjQqs75DVPd/LG7krmaFwONU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=OYE/baFK1amumWqel3sL8cMrJ8BB4n0ctqFm30il2gTUlWfbP1utk2b+XSdLbQjG4 i6jezwXJNyoccxd76beQTaw4RmybG23uouRxlEeWey4MpPK4QF6Zg/Mmtb7OTsn6KF xu8KyAgxvKN79tzldYlmyckCWOVNADFSmdvyHc0okMwJRb7263Ha439IVH98JDLw3g nJI3WKKKu6vjV1snRY2D0TVe9hoib6PAGIjv0/cprnIRSjseXu5QHq8K0kQuXDrv+e tE4Rn6wTA7D+xZdbmI+tPHPVGUtA/kZzpTd3T8FTtAOUG5jImh2IdSF07fLjKJ0ks/ 521GNOiyw4Lxg== Date: Sun, 6 Oct 2024 15:25:33 +0100 From: Jonathan Cameron To: Mohammed Anees Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Hennerich , Kim Seer Paller , Lars-Peter Clausen Subject: Re: [PATCH v2] iioc: dac: ltc2664: Fix span variable usage in ltc2664_channel_config function Message-ID: <20241006152533.329d9b59@jic23-huawei> In-Reply-To: <20241005170722.19542-1-pvmohammedanees2003@gmail.com> References: <20241005170722.19542-1-pvmohammedanees2003@gmail.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 5 Oct 2024 22:37:22 +0530 Mohammed Anees wrote: > In the current implementation of the ltc2664_channel_config function, > a variable named span is declared and initialized to 0, intended to > capture the return value of the ltc2664_set_span function. However, > the output of ltc2664_set_span is directly assigned to chan->span, > leaving span unchanged. As a result, when the function later checks > if (span < 0), this condition will never trigger an error since > span remains 0, this flaw leads to ineffective error handling. The > current patch resolves this issue by using the ret variable for > getting the return value, later assigning if successful and also > effectively removing span variable. > > Signed-off-by: Mohammed Anees > Fixes: 4cc2fc445d2e4e63ed6bd5d310752d88d365f8e4 > --- > v2: > - Using the ret variable to store the result from ltc2664_set_span > --- > drivers/iio/dac/ltc2664.c | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) > > diff --git a/drivers/iio/dac/ltc2664.c b/drivers/iio/dac/ltc2664.c > index 5be5345ac5c8..7dafcba7ece7 100644 > --- a/drivers/iio/dac/ltc2664.c > +++ b/drivers/iio/dac/ltc2664.c > @@ -516,7 +516,7 @@ static int ltc2664_channel_config(struct ltc2664_state *st) > const struct ltc2664_chip_info *chip_info = st->chip_info; > struct device *dev = &st->spi->dev; > u32 reg, tmp[2], mspan; > - int ret, span = 0; > + int ret; > > mspan = LTC2664_MSPAN_SOFTSPAN; > ret = device_property_read_u32(dev, "adi,manual-span-operation-config", > @@ -579,20 +579,24 @@ static int ltc2664_channel_config(struct ltc2664_state *st) > ret = fwnode_property_read_u32_array(child, "output-range-microvolt", > tmp, ARRAY_SIZE(tmp)); > if (!ret && mspan == LTC2664_MSPAN_SOFTSPAN) { > - chan->span = ltc2664_set_span(st, tmp[0] / 1000, > + ret = ltc2664_set_span(st, tmp[0] / 1000, > tmp[1] / 1000, reg); > - if (span < 0) > - return dev_err_probe(dev, span, > + if (ret < 0) > + return dev_err_probe(dev, ret, > "Failed to set span\n"); > + else else is unnecessary here as we have the standard check and error and return if set pattern. > + chan->span = ret; > } > > ret = fwnode_property_read_u32_array(child, "output-range-microamp", > tmp, ARRAY_SIZE(tmp)); > if (!ret) { > - chan->span = ltc2664_set_span(st, 0, tmp[1] / 1000, reg); > - if (span < 0) > - return dev_err_probe(dev, span, > + ret = ltc2664_set_span(st, 0, tmp[1] / 1000, reg); > + if (ret < 0) > + return dev_err_probe(dev, ret, > "Failed to set span\n"); > + else and here. > + chan->span = ret; > } > } >