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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A5925C49ED7 for ; Fri, 20 Sep 2019 14:38:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 863892080F for ; Fri, 20 Sep 2019 14:38:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392974AbfITOil (ORCPT ); Fri, 20 Sep 2019 10:38:41 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35630 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728948AbfITOY6 (ORCPT ); Fri, 20 Sep 2019 10:24:58 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqC-0004wB-HD; Fri, 20 Sep 2019 15:24:56 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqB-0007pV-Ss; Fri, 20 Sep 2019 15:24:55 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Hans Verkuil" , "Nathan Chancellor" , "Arnd Bergmann" , "Lad, Prabhakar" , "Mauro Carvalho Chehab" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 012/132] media: davinci-isif: avoid uninitialized variable use In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann commit 0e633f97162c1c74c68e2eb20bbd9259dce87cd9 upstream. clang warns about a possible variable use that gcc never complained about: drivers/media/platform/davinci/isif.c:982:32: error: variable 'frame_size' is uninitialized when used here [-Werror,-Wuninitialized] dm365_vpss_set_pg_frame_size(frame_size); ^~~~~~~~~~ drivers/media/platform/davinci/isif.c:887:2: note: variable 'frame_size' is declared here struct vpss_pg_frame_size frame_size; ^ 1 error generated. There is no initialization for this variable at all, and there has never been one in the mainline kernel, so we really should not put that stack data into an mmio register. On the other hand, I suspect that gcc checks the condition more closely and notices that the global isif_cfg.bayer.config_params.test_pat_gen flag is initialized to zero and never written to from any code path, so anything depending on it can be eliminated. To shut up the clang warning, just remove the dead code manually, it has probably never been used because any attempt to do so would have resulted in undefined behavior. Fixes: 63e3ab142fa3 ("V4L/DVB: V4L - vpfe capture - source for ISIF driver on DM365") Signed-off-by: Arnd Bergmann Reviewed-by: Nathan Chancellor Acked-by: Lad, Prabhakar Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Ben Hutchings --- drivers/media/platform/davinci/isif.c | 9 --------- 1 file changed, 9 deletions(-) --- a/drivers/media/platform/davinci/isif.c +++ b/drivers/media/platform/davinci/isif.c @@ -890,9 +890,7 @@ static int isif_set_hw_if_params(struct static int isif_config_ycbcr(void) { struct isif_ycbcr_config *params = &isif_cfg.ycbcr; - struct vpss_pg_frame_size frame_size; u32 modeset = 0, ccdcfg = 0; - struct vpss_sync_pol sync; dev_dbg(isif_cfg.dev, "\nStarting isif_config_ycbcr..."); @@ -980,13 +978,6 @@ static int isif_config_ycbcr(void) /* two fields are interleaved in memory */ regw(0x00000249, SDOFST); - /* Setup test pattern if enabled */ - if (isif_cfg.bayer.config_params.test_pat_gen) { - sync.ccdpg_hdpol = params->hd_pol; - sync.ccdpg_vdpol = params->vd_pol; - dm365_vpss_set_sync_pol(sync); - dm365_vpss_set_pg_frame_size(frame_size); - } return 0; }