From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BA42C433E2 for ; Thu, 3 Sep 2020 14:52:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5511520716 for ; Thu, 3 Sep 2020 14:52:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599144740; bh=JYgbbIOnVmePMIhUu47A7uGnn4+Zd9gZZZsHfVycOgE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=MX86OlBUo7TZPNC8ANcJvIdLX8TRGrwRJ2FuAcE6VlW28nUVX+cPVM+pEEcss/Ccz G/JWeKWYVOqcYFYv+x5K9vtq7ufyey2aZyGTPINqf49eqVkKkZmH3fStl6xQqIZzDr HxrpujIHZVD+6dhpeOB3APH0myi/13vOiifHpTro= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729020AbgICOwQ (ORCPT ); Thu, 3 Sep 2020 10:52:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:55468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729115AbgICONd (ORCPT ); Thu, 3 Sep 2020 10:13:33 -0400 Received: from coco.lan (ip5f5ad5c3.dynamic.kabel-deutschland.de [95.90.213.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4E41F20658; Thu, 3 Sep 2020 14:13:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599142412; bh=JYgbbIOnVmePMIhUu47A7uGnn4+Zd9gZZZsHfVycOgE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=YJCkDFUJUvutpZBXLk/07WqO2YV/zHF1gkcumsS7eAmPdkyhZE33Hr3pGUxJ1dbkK GRX+ovMcsOrFmDtzGTGfFT1nLG93+yUzGQygX43QAO/HxgIorhSeG81GqB64ELtG5N NABXpLxp8H8NherI6brOGBGo8kEanICIyESU0w8w= Date: Thu, 3 Sep 2020 16:13:28 +0200 From: Mauro Carvalho Chehab To: trix@redhat.com Cc: jasmin@anw.at, o.endriss@gmx.de, rjkm@metzlerbros.de, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] media: dvb-frontends/cxd2099: report errors Message-ID: <20200903161328.62378992@coco.lan> In-Reply-To: <20200722134126.31191-1-trix@redhat.com> References: <20200722134126.31191-1-trix@redhat.com> X-Mailer: Claws Mail 3.17.6 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Em Wed, 22 Jul 2020 06:41:26 -0700 trix@redhat.com escreveu: > From: Tom Rix > > Clang static analysis reports this error > > drivers/media/dvb-frontends/cxd2099.c:420:2: warning: Undefined > or garbage value returned to caller > return val; > ^~~~~~~~~~ > > In read_cam_control, the call to read_io can fail. > When it fails val is not set. > > The failure status should be returned to the caller, > not the unset val. > > Similar problem with read_attribute_mem > > Fixes: 0f0b270f905b ("[media] ngene: CXD2099AR Common Interface driver") > > Signed-off-by: Tom Rix > --- > drivers/media/dvb-frontends/cxd2099.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/dvb-frontends/cxd2099.c b/drivers/media/dvb-frontends/cxd2099.c > index f88b5355493e..9dfaf18fc4b4 100644 > --- a/drivers/media/dvb-frontends/cxd2099.c > +++ b/drivers/media/dvb-frontends/cxd2099.c > @@ -387,12 +387,15 @@ static int read_attribute_mem(struct dvb_ca_en50221 *ca, > { > struct cxd *ci = ca->data; > u8 val; > + int ret; > > mutex_lock(&ci->lock); > set_mode(ci, 1); > - read_pccard(ci, address, &val, 1); > + ret = read_pccard(ci, address, &val, 1); > + if (!ret) > + ret = val; > mutex_unlock(&ci->lock); > - return val; > + return ret; > } > > static int write_attribute_mem(struct dvb_ca_en50221 *ca, int slot, > @@ -412,12 +415,15 @@ static int read_cam_control(struct dvb_ca_en50221 *ca, > { > struct cxd *ci = ca->data; > unsigned int val; > + int ret; > > mutex_lock(&ci->lock); > set_mode(ci, 0); > - read_io(ci, address, &val); > + ret = read_io(ci, address, &val); > + if (!ret) > + ret = val; > mutex_unlock(&ci->lock); > - return val; > + return ret; > } > > static int write_cam_control(struct dvb_ca_en50221 *ca, int slot, Hmm... Had you test this one on a real hardware? It is not uncommon to have some DVB devices that would fail reading when the firmware is on cold state. Without testing a patch like that at a real hardware, there's no way to know if this is intentional or if the original developer forgot to add a check for the error. So, at most, it could print some warning message for non-zero return codes. Thanks, Mauro