From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59B8EC433E2 for ; Thu, 10 Sep 2020 13:33:56 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 166F8208E4 for ; Thu, 10 Sep 2020 13:33:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 166F8208E4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6D1EF6E0D3; Thu, 10 Sep 2020 13:33:55 +0000 (UTC) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id D15446E0D3 for ; Thu, 10 Sep 2020 13:33:53 +0000 (UTC) IronPort-SDR: 5VVdRmwflKY0JbCj+/3Tox95Tpv9aDts2nZdo7r6y4R86emWQ/yPrCML9mECkqXjtuYgFsR02Q crVMy4h5e/Dw== X-IronPort-AV: E=McAfee;i="6000,8403,9739"; a="138563244" X-IronPort-AV: E=Sophos;i="5.76,413,1592895600"; d="scan'208";a="138563244" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Sep 2020 06:33:53 -0700 IronPort-SDR: cQvBgO3WYSnb7TgZAHyKH+l5oTkO0rLJ8LxL6suKqLA0ld5VuD4fhLKpsN9T8H8GS4lxMeUa8N ZFkKiEBVsEfw== X-IronPort-AV: E=Sophos;i="5.76,413,1592895600"; d="scan'208";a="480890694" Received: from nfhickey-mobl.ger.corp.intel.com (HELO localhost) ([10.251.81.64]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Sep 2020 06:33:52 -0700 From: Jani Nikula To: Uma Shankar , intel-gfx@lists.freedesktop.org In-Reply-To: <20200910121153.6749-1-uma.shankar@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20200910121153.6749-1-uma.shankar@intel.com> Date: Thu, 10 Sep 2020 16:33:53 +0300 Message-ID: <878sdh21tq.fsf@intel.com> MIME-Version: 1.0 Subject: Re: [Intel-gfx] [PATCH] drm/i915/display: Add a vblank wait for FBC activation within same frame X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, 10 Sep 2020, Uma Shankar wrote: > Add a vblank wait when fbc activation request comes for the > same frame on TGL. This helps fix underrun related to fbc. > > Signed-off-by: Uma Shankar > --- > drivers/gpu/drm/i915/display/intel_fbc.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c > index 135f5e8a4d70..3e1d715e4a4e 100644 > --- a/drivers/gpu/drm/i915/display/intel_fbc.c > +++ b/drivers/gpu/drm/i915/display/intel_fbc.c > @@ -1055,6 +1055,7 @@ static void __intel_fbc_post_update(struct intel_crtc *crtc) > { > struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); > struct intel_fbc *fbc = &dev_priv->fbc; > + static u32 old_frame_cnt, new_frame_cnt; In the strongest terms, do not add static data. These would be shared across devices, which is certainly a bug. BR, Jani. > > drm_WARN_ON(&dev_priv->drm, !mutex_is_locked(&fbc->lock)); > > @@ -1075,10 +1076,18 @@ static void __intel_fbc_post_update(struct intel_crtc *crtc) > if (!intel_fbc_can_activate(crtc)) > return; > > - if (!fbc->busy_bits) > + old_frame_cnt = new_frame_cnt; > + new_frame_cnt = intel_crtc_get_vblank_counter(crtc); > + if (!fbc->busy_bits) { > + if (IS_TIGERLAKE(dev_priv) && > + old_frame_cnt == new_frame_cnt) { > + drm_dbg_kms(&dev_priv->drm, "Wait for vblank before Activating FBC"); > + intel_wait_for_vblank_if_active(dev_priv, crtc->pipe); > + } > intel_fbc_hw_activate(dev_priv); > - else > + } else { > intel_fbc_deactivate(dev_priv, "frontbuffer write"); > + } > } > > void intel_fbc_post_update(struct intel_atomic_state *state, -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx