From patchwork Tue Oct 26 09:34:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jani Nikula X-Patchwork-Id: 12584327 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 644B5C433F5 for ; Tue, 26 Oct 2021 09:34:16 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 0FDC2604DC for ; Tue, 26 Oct 2021 09:34:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0FDC2604DC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 43D186E419; Tue, 26 Oct 2021 09:34:15 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7C06B6E419 for ; Tue, 26 Oct 2021 09:34:14 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10148"; a="230141002" X-IronPort-AV: E=Sophos;i="5.87,182,1631602800"; d="scan'208";a="230141002" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2021 02:34:14 -0700 X-IronPort-AV: E=Sophos;i="5.87,182,1631602800"; d="scan'208";a="486106238" Received: from flaboura-mobl.ger.corp.intel.com (HELO localhost) ([10.251.214.127]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2021 02:34:11 -0700 From: Jani Nikula To: Jani Nikula , intel-gfx@lists.freedesktop.org Cc: Manasi Navare , =?utf-8?b?VmlsbGUgU3lyasOk?= =?utf-8?b?bMOk?= Date: Tue, 26 Oct 2021 12:34:07 +0300 Message-Id: <20211026093407.11381-1-jani.nikula@intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211026084208.2574-1-jani.nikula@intel.com> References: <20211026084208.2574-1-jani.nikula@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Subject: [Intel-gfx] [PATCH v2] drm/i915/dp: fix integer overflow in 128b/132b data rate calculation X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" The intermediate value 1000000 * 10 * 9671 overflows 32 bits, so force promotion to a bigger type. From the logs: [drm:intel_dp_compute_config [i915]] DP link rate required 3657063 available -580783288 v2: Use mul_u32_u32() (Ville) Fixes: 48efd014f0ea ("drm/i915/dp: add max data rate calculation for UHBR rates") Cc: Manasi Navare Cc: Ville Syrjälä Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/display/intel_dp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index f5dc2126d140..537c689a1528 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -352,7 +352,7 @@ intel_dp_max_data_rate(int max_link_rate, int max_lanes) */ int max_link_rate_kbps = max_link_rate * 10; - max_link_rate_kbps = DIV_ROUND_CLOSEST_ULL(max_link_rate_kbps * 9671, 10000); + max_link_rate_kbps = DIV_ROUND_CLOSEST_ULL(mul_u32_u32(max_link_rate_kbps, 9671), 10000); max_link_rate = max_link_rate_kbps / 8; }