From patchwork Mon Aug 29 16:31:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: cpaul@redhat.com X-Patchwork-Id: 9304147 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 E626A6077C for ; Mon, 29 Aug 2016 16:31:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CF6002874A for ; Mon, 29 Aug 2016 16:31:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C3FAA28751; Mon, 29 Aug 2016 16:31:35 +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 D74F92874A for ; Mon, 29 Aug 2016 16:31:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2308D6E5BC; Mon, 29 Aug 2016 16:31:33 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0BA356E5BC; Mon, 29 Aug 2016 16:31:32 +0000 (UTC) Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9467083F38; Mon, 29 Aug 2016 16:31:31 +0000 (UTC) Received: from ecstaticemu.bos.redhat.com (dhcp-25-87.bos.redhat.com [10.18.25.87]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u7TGVUFP015924; Mon, 29 Aug 2016 12:31:30 -0400 From: Lyude To: Jani Nikula Date: Mon, 29 Aug 2016 12:31:27 -0400 Message-Id: <1472488288-27280-1-git-send-email-cpaul@redhat.com> In-Reply-To: <871t17ipah.fsf@intel.com> References: <871t17ipah.fsf@intel.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 29 Aug 2016 16:31:31 +0000 (UTC) Cc: David Airlie , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter Subject: [Intel-gfx] [PATCH v3] drm/i915/skl: Don't try to update plane watermarks if they haven't changed 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 i915 sometimes needs to disable planes in the middle of an atomic commit, and then reenable them later in the same commit. Because of this, we can't make the assumption that the state of the plane actually changed. Since the state of the plane hasn't actually changed, neither have it's watermarks. And if the watermarks hasn't changed then we haven't populated skl_results with anything, which means we'll end up zeroing out a plane's watermarks in the middle of the atomic commit without restoring them later. Simple reproduction recipe: - Get a SKL laptop, launch any kind of X session - Get two extra monitors - Keep hotplugging both displays (so that the display configuration jumps from 1 active pipe to 3 active pipes and back) - Eventually underrun Changes since v1: - Fix incorrect use of "it's" Changes since v2: - Add reproduction recipe Signed-off-by: Lyude Cc: Maarten Lankhorst Fixes: 62e0fb880123 ("drm/i915/skl: Update plane watermarks atomically during plane updates") Signed-off-by: Lyude --- drivers/gpu/drm/i915/intel_display.c | 7 ++++++- drivers/gpu/drm/i915/intel_sprite.c | 9 +++++++-- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index e4e6141..13e47a7 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3448,7 +3448,12 @@ static void skylake_disable_primary_plane(struct drm_plane *primary, struct intel_crtc *intel_crtc = to_intel_crtc(crtc); int pipe = intel_crtc->pipe; - skl_write_plane_wm(intel_crtc, &dev_priv->wm.skl_results, 0); + /* + * We only populate skl_results on watermark updates, and if the + * plane's visiblity isn't actually changing neither is its watermarks. + */ + if (!crtc->primary->state->visible) + skl_write_plane_wm(intel_crtc, &dev_priv->wm.skl_results, 0); I915_WRITE(PLANE_CTL(pipe, 0), 0); I915_WRITE(PLANE_SURF(pipe, 0), 0); diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c index 0df783a..73a521f 100644 --- a/drivers/gpu/drm/i915/intel_sprite.c +++ b/drivers/gpu/drm/i915/intel_sprite.c @@ -292,8 +292,13 @@ skl_disable_plane(struct drm_plane *dplane, struct drm_crtc *crtc) const int pipe = intel_plane->pipe; const int plane = intel_plane->plane + 1; - skl_write_plane_wm(to_intel_crtc(crtc), &dev_priv->wm.skl_results, - plane); + /* + * We only populate skl_results on watermark updates, and if the + * plane's visiblity isn't actually changing neither is its watermarks. + */ + if (!dplane->state->visible) + skl_write_plane_wm(to_intel_crtc(crtc), + &dev_priv->wm.skl_results, plane); I915_WRITE(PLANE_CTL(pipe, plane), 0);