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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C5D81C76190 for ; Thu, 25 Jul 2019 18:56:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A2CD1206DD for ; Thu, 25 Jul 2019 18:56:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="CtAUXQqT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A2CD1206DD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=tUHLEdmAJRJCX0ajohRWtoGU49L1MDpwPLN3Nnem/P0=; b=CtAUXQqT8CdYVu oLw13otp6MLpqkwdEJhz5/qY1qHDGeYZcpqrvbEa8sT3M2/zg2243OsjD8OifJ29Kpw+uU1Glrrrj FgvHwGEU444tyQu5Sa2W37+oolE6Ps+9NnkSOLAml8Yc34kbUxKi7c+hyq1tDA25AyEgemuSs/5v2 W/YUKw/ZygQ1WhhAKpcb9eV/u26Ux2RYbhwiV1sfOA5HY3hLnC6hmU6JpaPR9ZmdNUozHnw1cbqk4 GQ56PVR0qaQDeLZySIpFscIb/aeLwNxyxwT3u1Y6CakpnEPlm4ArkTPMtBlCxmhS1u2Hv5ScZpHfY s5Pui3mHYTJrX92XCWeQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hqiuq-0006NN-0F; Thu, 25 Jul 2019 18:56:36 +0000 Received: from relay2-d.mail.gandi.net ([217.70.183.194]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hqium-0006KT-0h for linux-arm-kernel@lists.infradead.org; Thu, 25 Jul 2019 18:56:33 +0000 X-Originating-IP: 93.29.109.196 Received: from localhost.localdomain (196.109.29.93.rev.sfr.net [93.29.109.196]) (Authenticated sender: paul.kocialkowski@bootlin.com) by relay2-d.mail.gandi.net (Postfix) with ESMTPSA id 0144940002; Thu, 25 Jul 2019 18:56:18 +0000 (UTC) From: Paul Kocialkowski To: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@googlegroups.com Subject: [PATCH v7 1/4] media: v4l2-ctrl: Add a comment on why we zero out compound controls fields Date: Thu, 25 Jul 2019 20:55:59 +0200 Message-Id: <20190725185602.22522-2-paul.kocialkowski@bootlin.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190725185602.22522-1-paul.kocialkowski@bootlin.com> References: <20190725185602.22522-1-paul.kocialkowski@bootlin.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190725_115632_216029_88B4F177 X-CRM114-Status: GOOD ( 10.48 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Hans Verkuil , Jernej Skrabec , Sakari Ailus , Alexandre Courbot , Jonas Karlman , Maxime Ripard , Greg Kroah-Hartman , Tomasz Figa , Paul Kocialkowski , Chen-Yu Tsai , Boris Brezillon , Nicolas Dufresne , Thomas Petazzoni , Mauro Carvalho Chehab , Ezequiel Garcia Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Since it's not necessarily very explicit why we need to zero some fields in std_validate_compound, add a comment before the function to explain why, which should help as a reminder. Signed-off-by: Paul Kocialkowski --- drivers/media/v4l2-core/v4l2-ctrls.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c index 76fa2db0e8fb..cd1ae016706f 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -1645,6 +1645,10 @@ static void std_log(const struct v4l2_ctrl *ctrl) #define zero_padding(s) \ memset(&(s).padding, 0, sizeof((s).padding)) +/* + * Compound controls validation requires setting unused fields/flags to zero + * in order to properly detect unchanged controls with std_equal's memcmp. + */ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx, union v4l2_ctrl_ptr ptr) { -- 2.22.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel