From patchwork Mon Feb 22 11:52:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tvrtko Ursulin X-Patchwork-Id: 8375901 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4E966C0553 for ; Mon, 22 Feb 2016 11:52:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ADE6020498 for ; Mon, 22 Feb 2016 11:52:35 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 964E52038D for ; Mon, 22 Feb 2016 11:52:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F0D676E15E; Mon, 22 Feb 2016 11:52:33 +0000 (UTC) X-Original-To: Intel-gfx@lists.freedesktop.org Delivered-To: Intel-gfx@lists.freedesktop.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTP id B1ACA6E15E for ; Mon, 22 Feb 2016 11:52:32 +0000 (UTC) Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP; 22 Feb 2016 03:52:32 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,484,1449561600"; d="scan'208";a="750875179" Received: from tursulin-linux.isw.intel.com ([10.102.226.196]) by orsmga003.jf.intel.com with ESMTP; 22 Feb 2016 03:52:30 -0800 From: Tvrtko Ursulin To: Intel-gfx@lists.freedesktop.org Date: Mon, 22 Feb 2016 11:52:28 +0000 Message-Id: <1456141948-7172-1-git-send-email-tvrtko.ursulin@linux.intel.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915: Avoid divbyzero in modesetting X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 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" X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00,HK_RANDOM_FROM, RCVD_IN_DNSWL_MED,RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Tvrtko Ursulin Not sure if intel_wm_config->num_pipes_active is supposed to ever be zero when intel_update_watermarks gets called. But since it can be triggered in early platform bringup perhaps we want to guard against it rather than divide by zero. Signed-off-by: Tvrtko Ursulin Cc: Matt Roper Cc: Ville Syrjälä Cc: Daniel Vetter Cc: Maarten Lankhorst --- drivers/gpu/drm/i915/intel_pm.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index feb57598727a..2b7998889617 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2831,8 +2831,13 @@ skl_ddb_get_pipe_allocation_limits(struct drm_device *dev, nth_active_pipe++; } - pipe_size = ddb_size / config->num_pipes_active; - alloc->start = nth_active_pipe * ddb_size / config->num_pipes_active; + if (WARN_ON(!config->num_pipes_active)) { + pipe_size = 0; + alloc->start = 0; + } else { + pipe_size = ddb_size / config->num_pipes_active; + alloc->start = nth_active_pipe * ddb_size / config->num_pipes_active; + } alloc->end = alloc->start + pipe_size; }