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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 70F30C98321 for ; Thu, 24 Sep 2026 18:41:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=2yRJjxTjeVzQgSJ7LXkMb/7lJ+YpfJPDRuPzfo2hYeI=; b=iBrIFjNAhndSFYhVM0tIdh9zoq G2KL0/w1A0Jg6eIrPpBW3YFivAD5JSFSzxbNVb+Go7wEIWJQEDzAoudHgfwdVJdMUBbz+IMojbrwa 9anQ8lJotn01fbOhGK+kaXPukqi0cK0M8AhEZvrSHvKGuAzwFkjlAgn7baYuPlLC89V08gwCFrMLo Ar8z/STwiZppeGpHq6OT3lVk7RgEQtR42pQNULV5CjeRXrNVzuzGwn2mWp2ezaVBUMsSpstlDYR7p rYb2Etgq7CmbV17JXbsnZtufv2dcNnVfNNmTKdNj74w/bMctcOhtVFn+OmvPI2VHt6AetrNGipEwm zFzl+SVQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9oNb-0000000Bw2Z-2jdp; Thu, 24 Sep 2026 18:41:11 +0000 Received: from pidgin.makrotopia.org ([2a07:2ec0:3002::65]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9oNS-0000000Bvrq-03ip; Thu, 24 Sep 2026 18:41:04 +0000 Received: from local by pidgin.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256:X25519MLKEM768) (Exim 4.100) (envelope-from ) id 1x9oNN-000000007Ly-0Z5c; Thu, 24 Sep 2026 18:40:57 +0000 Date: Thu, 24 Sep 2026 19:40:54 +0100 From: Daniel Golle To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Matthias Brugger , AngeloGioacchino Del Regno , Allen Chen , Hermes Wu , Pin-yen Lin , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH v7 07/14] drm/bridge: it6505: avoid division by zero in pixel clock calculation Message-ID: <0b274e5636cdbf48a5d287fb2132a162f05f5dfb.1790275151.git.daniel@makrotopia.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260924_114102_056407_593159BA X-CRM114-Status: GOOD ( 10.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org it6505_calc_video_info() checks the sum of the three pixel clock counter samples for zero before dividing it by 3, so sums of 1 or 2 truncate to 0 and the following pixel clock calculation divides by zero. Divide first and check the result. Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver") Signed-off-by: Daniel Golle --- v7: no changes v6: no changes v5: new patch --- drivers/gpu/drm/bridge/ite-it6505.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index 42106bc2056e..180a270ecfc1 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -751,12 +751,13 @@ static void it6505_calc_video_info(struct it6505 *it6505) sum += rddata; } + sum /= 3; + if (sum == 0) { DRM_DEV_DEBUG_DRIVER(dev, "calc video timing error"); return; } - sum /= 3; pclk = 13500 * 2048 / sum; it6505->video_info.clock = pclk; it6505->video_info.hdisplay = hdew; -- 2.55.0