From patchwork Tue Oct 21 10:46:31 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5114901 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E4238C11AC for ; Tue, 21 Oct 2014 11:13:31 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 25BA820145 for ; Tue, 21 Oct 2014 11:13:31 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4402320138 for ; Tue, 21 Oct 2014 11:13:30 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id C92C3B44; Tue, 21 Oct 2014 11:01:05 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 0D8FCC97 for ; Tue, 21 Oct 2014 11:01:05 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id A07EF1FB50 for ; Tue, 21 Oct 2014 11:01:04 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 21 Oct 2014 04:01:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617793061" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:01:03 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:46:31 +0800 Message-Id: <1413889294-31328-192-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Subject: [LTSI-dev] [PATCH 0191/1094] drm/i915: remove the vblank_wait hack from HSW+ X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Paulo Zanoni When I forked haswell_crtc_enable I copied all the code from ironlake_crtc_enable. The last piece of the function contains a big comment with a call to intel_wait_for_vblank. After this fork, we rearranged the Haswell code so that it enables the planes as the very last step of the modeset sequence, so we're sure that we call intel_enable_primary_plane after the pipe is really running, so the vblank waiting functions work as expected. I really believe this is what fixes the problem described by the big comment, so let's give it a try and get rid of that intel_wait_for_vblank, saving around 16ms per modeset (and init/resume). We can always revert if needed :) Signed-off-by: Paulo Zanoni Reviewed-by: Jesse Barnes Signed-off-by: Daniel Vetter (cherry picked from commit 3fddd40739de9c08099d1d488d24c42e0c210d6b) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/i915/intel_display.c | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b238ffa..ccb0089 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3761,16 +3761,6 @@ static void haswell_crtc_enable(struct drm_crtc *crtc) * to change the workaround. */ haswell_mode_set_planes_workaround(intel_crtc); haswell_crtc_enable_planes(crtc); - - /* - * There seems to be a race in PCH platform hw (at least on some - * outputs) where an enabled pipe still completes any pageflip right - * away (as if the pipe is off) instead of waiting for vblank. As soon - * as the first vblank happend, everything works as expected. Hence just - * wait for one vblank before returning to avoid strange things - * happening. - */ - intel_wait_for_vblank(dev, intel_crtc->pipe); } static void ironlake_pfit_disable(struct intel_crtc *crtc)