From patchwork Wed Dec 14 14:55:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zanoni, Paulo R" X-Patchwork-Id: 9474321 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BD9576021C for ; Wed, 14 Dec 2016 14:55:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B012E28713 for ; Wed, 14 Dec 2016 14:55:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2B5D286F4; Wed, 14 Dec 2016 14:55:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 720B2286F4 for ; Wed, 14 Dec 2016 14:55:55 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AD87E6E82E; Wed, 14 Dec 2016 14:55:54 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8DFA189A44 for ; Wed, 14 Dec 2016 14:55:46 +0000 (UTC) Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP; 14 Dec 2016 06:55:46 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,347,1477983600"; d="scan'208";a="39913880" Received: from przanoni-mobl.amr.corp.intel.com ([10.254.182.181]) by orsmga004.jf.intel.com with ESMTP; 14 Dec 2016 06:55:44 -0800 From: Paulo Zanoni To: intel-gfx@lists.freedesktop.org Date: Wed, 14 Dec 2016 12:55:38 -0200 Message-Id: <1481727338-9901-2-git-send-email-paulo.r.zanoni@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1481727338-9901-1-git-send-email-paulo.r.zanoni@intel.com> References: <1481727338-9901-1-git-send-email-paulo.r.zanoni@intel.com> Cc: Paulo Zanoni Subject: [Intel-gfx] [PATCH 2/2] drm/i915: fully apply WaSkipStolenMemoryFirstPage 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: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Reserve the first page of stolen memory right after initializing the mm allocator. This means that we won't inherit the FB in case the BIOS decides to put it at the start of stolen. But the BIOS should not be putting it at the start of stolen since it's going to get corrupted. I suppose the bug here is that some pixels at the very top of the screen will be corrupted, so it's not exactly easy to notice. We have confirmation that the first page of stolen does actually get corrupted, so I really think we should do this in order to avoid any possible future headaches, even if that means losing BIOS framebuffer inheritance. Let's not use the HW in a way it's not supposed to be used. v2: don't even put the first page on the mm (Chris). Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94605 Cc: Chris Wilson Signed-off-by: Paulo Zanoni Reviewed-by: Chris Wilson --- drivers/gpu/drm/i915/i915_gem_stolen.c | 27 ++++++++------------------- 1 file changed, 8 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index b1c8897..7435540 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -54,12 +54,6 @@ int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *dev_priv, if (!drm_mm_initialized(&dev_priv->mm.stolen)) return -ENODEV; - /* See the comment at the drm_mm_init() call for more about this check. - * WaSkipStolenMemoryFirstPage:bdw+ (incomplete) - */ - if (start < 4096 && INTEL_GEN(dev_priv) >= 8) - start = 4096; - mutex_lock(&dev_priv->mm.stolen_lock); ret = drm_mm_insert_node_in_range(&dev_priv->mm.stolen, node, size, alignment, start, end, @@ -410,7 +404,7 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv) { struct i915_ggtt *ggtt = &dev_priv->ggtt; unsigned long reserved_total, reserved_base = 0, reserved_size; - unsigned long stolen_top; + unsigned long stolen_start = 0, stolen_top; mutex_init(&dev_priv->mm.stolen_lock); @@ -491,18 +485,13 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv) ggtt->stolen_usable_size = ggtt->stolen_size - reserved_total; - /* - * Basic memrange allocator for stolen space. - * - * TODO: Notice that some platforms require us to not use the first page - * of the stolen memory but their BIOSes may still put the framebuffer - * on the first page. So we don't reserve this page for now because of - * that. Our current solution is to just prevent new nodes from being - * inserted on the first page - see the check we have at - * i915_gem_stolen_insert_node_in_range(). We may want to fix the fbcon - * problem later. - */ - drm_mm_init(&dev_priv->mm.stolen, 0, ggtt->stolen_usable_size); + /* WaSkipStolenMemoryFirstPage:bdw+ */ + if (INTEL_GEN(dev_priv) >= 8) + stolen_start = 4096; + + /* Basic memrange allocator for stolen space. */ + drm_mm_init(&dev_priv->mm.stolen, stolen_start, + ggtt->stolen_usable_size); return 0; }