From patchwork Thu Jul 18 14:54:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11049207 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 64DA913BD for ; Thu, 18 Jul 2019 14:54:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5239A206AF for ; Thu, 18 Jul 2019 14:54:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 437A628785; Thu, 18 Jul 2019 14:54:19 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 D4DD5206AF for ; Thu, 18 Jul 2019 14:54:18 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D36AD6E3DA; Thu, 18 Jul 2019 14:54:17 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2473C6E3DA for ; Thu, 18 Jul 2019 14:54:17 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 17402280-1500050 for multiple; Thu, 18 Jul 2019 15:54:09 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Thu, 18 Jul 2019 15:54:04 +0100 Message-Id: <20190718145407.21352-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 1/4] drm/i915: Drop wmb() inside pread_gtt X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 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-Virus-Scanned: ClamAV using ClamSMTP Inside pread, we only ever read from the GTT so the serialising wmb() instructions around the GGTT PTE updates are pointless. Signed-off-by: Chris Wilson Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/i915_gem.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index a207b90924e4..fed0bc421a55 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -395,11 +395,9 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj, unsigned page_length = PAGE_SIZE - page_offset; page_length = remain < page_length ? remain : page_length; if (node.allocated) { - wmb(); ggtt->vm.insert_page(&ggtt->vm, i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT), node.start, I915_CACHE_NONE, 0); - wmb(); } else { page_base += offset & PAGE_MASK; } @@ -419,7 +417,6 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj, out_unpin: mutex_lock(&i915->drm.struct_mutex); if (node.allocated) { - wmb(); ggtt->vm.clear_range(&ggtt->vm, node.start, node.size); remove_mappable_node(&node); } else {