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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 714C3C433F5 for ; Thu, 30 Sep 2021 07:41:48 +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 2AF0861527 for ; Thu, 30 Sep 2021 07:41:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2AF0861527 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=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ACEB96E342; Thu, 30 Sep 2021 07:41:47 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id AD27A6E342 for ; Thu, 30 Sep 2021 07:41:45 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10122"; a="221922422" X-IronPort-AV: E=Sophos;i="5.85,335,1624345200"; d="scan'208";a="221922422" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Sep 2021 00:41:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.85,335,1624345200"; d="scan'208";a="520249470" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.171]) by fmsmga008.fm.intel.com with SMTP; 30 Sep 2021 00:41:40 -0700 Received: by stinkbox (sSMTP sendmail emulation); Thu, 30 Sep 2021 10:41:39 +0300 Date: Thu, 30 Sep 2021 10:41:39 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: =?iso-8859-1?Q?Jos=E9?= Roberto de Souza Cc: intel-gfx@lists.freedesktop.org, Gwan-gyeong Mun Message-ID: References: <20210930001409.254817-1-jose.souza@intel.com> <20210930001409.254817-3-jose.souza@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210930001409.254817-3-jose.souza@intel.com> X-Patchwork-Hint: comment Subject: Re: [Intel-gfx] [PATCH v2 3/9] drm/i915/display: Drop unnecessary frontbuffer flushes 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, Sep 29, 2021 at 05:14:03PM -0700, José Roberto de Souza wrote: > This unnecessary flushes are hurting power-savings are it causes > features like PSR, FBC and DRRS to disable it self to handle > frontbuffer rendering, below some explanation of why each removed > call is not necessary. > > The flush in intel_prepare_plane_fb() is not required as framebuffer > will be flipped and power-saving features do the proper flip handling > in hardware. > > intel_find_initial_plane_obj() flush is not required because it is > only executed during driver load and at this point the power-saving > features are not even enabled. > > And the last one intelfb_create(), is also not required as at this > point the fbdev was just allocated, userspace will draw on > it what will trigger frontbuffer invalidates and flushes later on. > > Cc: Ville Syrjälä > Cc: Gwan-gyeong Mun > Signed-off-by: José Roberto de Souza Yeah, I think these are not right. We might have to think a bit more about page flips vs. frontbuffer tracking at some point. But at least FBC doesn't want these, and for drrs I think you added something to the flip path (also drrs is kinda semi borked anyway atm and needs some real fixing). So lgtm Reviewed-by: Ville Syrjälä > --- > drivers/gpu/drm/i915/display/intel_display.c | 3 --- > drivers/gpu/drm/i915/display/intel_fbdev.c | 2 -- > 2 files changed, 5 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > index 4ce80ca7751f0..9e9db1b0a907b 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.c > +++ b/drivers/gpu/drm/i915/display/intel_display.c > @@ -1711,8 +1711,6 @@ intel_find_initial_plane_obj(struct intel_crtc *crtc, > plane_state->uapi.crtc = &crtc->base; > intel_plane_copy_uapi_to_hw_state(plane_state, plane_state, crtc); > > - intel_frontbuffer_flush(to_intel_frontbuffer(fb), ORIGIN_DIRTYFB); > - > atomic_or(plane->frontbuffer_bit, &to_intel_frontbuffer(fb)->bits); > } > > @@ -10755,7 +10753,6 @@ intel_prepare_plane_fb(struct drm_plane *_plane, > return ret; > > i915_gem_object_wait_priority(obj, 0, &attr); > - i915_gem_object_flush_frontbuffer(obj, ORIGIN_DIRTYFB); > > if (!new_plane_state->uapi.fence) { /* implicit fencing */ > struct dma_fence *fence; > diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c > index 60d3ded270476..53484267b2a4a 100644 > --- a/drivers/gpu/drm/i915/display/intel_fbdev.c > +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c > @@ -230,8 +230,6 @@ static int intelfb_create(struct drm_fb_helper *helper, > goto out_unlock; > } > > - intel_frontbuffer_flush(to_frontbuffer(ifbdev), ORIGIN_DIRTYFB); > - > info = drm_fb_helper_alloc_fbi(helper); > if (IS_ERR(info)) { > drm_err(&dev_priv->drm, "Failed to allocate fb_info\n"); > -- > 2.33.0 -- Ville Syrjälä Intel