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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 88BDBC433F5 for ; Tue, 1 Feb 2022 13:45:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F1B7B10E1E6; Tue, 1 Feb 2022 13:45:39 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id BFA6510E410 for ; Tue, 1 Feb 2022 13:45:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643723138; x=1675259138; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=V1xbQYUVnAoaRcJJt8Yz1Xdxc6hxyvaDFOnlieNBSfw=; b=PaPxQ6bIkrrD9SK0RK5Hn+/uMsHzCVDhw//m9j9NT0JZD48A5PcEVzzX PGr5FSswmCGJGZAFMaKTbJtqZf/42wc68nNBeKFJkEQR+v8JeZSgAosZw Diizec9xcjUfubpkDV3xunKwpTuaIXrBRQJPKqiBvyuyE//WXptTeKvBq K8rhURgM8z1Io5ku2/5l8b4g8xRu7eNSPYMem+Lcl0CXhQk1k2zkMXAik Vi1Zi89xFbIVja60Td9Ddhh5ZvXBuAbfzjuJ3Ag66l8Fhm07tv74wlmfG fH4lgKs0vrEO9+7qwUKU5wydsHjaUgR8B92UIx5wAKwBwlo5oUmePBzdC w==; X-IronPort-AV: E=McAfee;i="6200,9189,10244"; a="231262328" X-IronPort-AV: E=Sophos;i="5.88,334,1635231600"; d="scan'208";a="231262328" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Feb 2022 05:45:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,334,1635231600"; d="scan'208";a="583033312" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by fmsmga008.fm.intel.com with SMTP; 01 Feb 2022 05:45:36 -0800 Received: by stinkbox (sSMTP sendmail emulation); Tue, 01 Feb 2022 15:45:35 +0200 Date: Tue, 1 Feb 2022 15:45:35 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: "Lisovskiy, Stanislav" Message-ID: References: <20220118092354.11631-1-ville.syrjala@linux.intel.com> <20220118092354.11631-12-ville.syrjala@linux.intel.com> <20220201085239.GA9569@intel.com> <20220201111818.GA10506@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220201111818.GA10506@intel.com> X-Patchwork-Hint: comment Subject: Re: [Intel-gfx] [PATCH 11/15] drm/i915: Nuke intel_bw_calc_min_cdclk() 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: , Cc: intel-gfx@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, Feb 01, 2022 at 01:18:18PM +0200, Lisovskiy, Stanislav wrote: > On Tue, Feb 01, 2022 at 12:05:13PM +0200, Ville Syrjälä wrote: > > On Tue, Feb 01, 2022 at 10:52:39AM +0200, Lisovskiy, Stanislav wrote: > > > On Tue, Jan 18, 2022 at 11:23:50AM +0200, Ville Syrjala wrote: > > > > From: Ville Syrjälä > > > > > > > > intel_bw_calc_min_cdclk() is entirely pointless. All it manages to do is > > > > somehow conflate the per-pipe min cdclk with dbuf min cdclk. There is no > > > > (at least documented) dbuf min cdclk limit on pre-skl so let's just get > > > > rid of all this confusion. > > > > > > > > Signed-off-by: Ville Syrjälä > > > > > > I think we constantly have a bit contradictional attitude towards such situation. > > > >From one perspective you can say, that those kind of "leagcy" callbacks are > > > pointless, from the other hand one might say. that we need to have a unified > > > approach for all platforms and I think we got, some legacy handlers for old > > > platforms for similar purpose as well. > > > I'm fine with both approaches, however for example when I was submitting > > > that patch, I was asked by reviewer to add this kind of legacy callback, so that we have > > > a "uniform" approach. > > > We just then need to have some standard agreement on those, which doesn't > > > depend on today's cosmic radiation levels :) > > > > Yes in general I prefer a unified approach across all platforms. > > But in this case there is nothing to do for the old platforms as they > > don't have any kind of dbuf cdclk limit, or if there is one we don't > > know what it is since it's not documented. > > > > So the only thing the code was really doing was conflating the > > per-pipe cdclk limit (which is handled elsewhere for all platforms > > in a unified fashion) with something that doesn't even exist. > > > > Also I don't think it was even correct anyway since it was > > using the per-pipe cdclk_state->min_cdclk[] already during > > intel_cdclk_atomic_check(), but cdclk_state->min_cdclk[] > > isn't even computed until intel_modeset_calc_cdclk() which > > is called later. So I guess it was basically just computing > > the max of the min_cdclk[] for all the pipes for the _old_ > > state, not the new state. > > No, I think actually the idea was that it was first calculating > new_bw_state->min_cdclk, based on plane and dbuf bandwidth requirements > in intel_atomic_check_cdclk, Well intel_bw_calc_min_cdclk() did none of that. Like I said it just took the max of the _old_ per-pipe cdclk_state->min_cdclk[] values and stored that as the *new* bw min cdclk, which later would get consulted by intel_compute_min_cdclk(). -- Ville Syrjälä Intel