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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3ECE5C5479D for ; Wed, 11 Jan 2023 15:05:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234467AbjAKPFf (ORCPT ); Wed, 11 Jan 2023 10:05:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238833AbjAKPEz (ORCPT ); Wed, 11 Jan 2023 10:04:55 -0500 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A5B210FE; Wed, 11 Jan 2023 07:04:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1673449495; x=1704985495; h=date:from:to:subject:message-id:references:mime-version: content-transfer-encoding:in-reply-to; bh=jxDJ3ooBqVnTaczv1GXFLe+oPshX0iJRCjOYwPWvPAA=; b=b+wYNn8bm9dndm/k3rnX4nARLMBPPUC+Dj3nzq4ku88Afs44J7oJW+DP EsuKTC5ryH3UI3PPKlVZDPHUA6Z6LnUDNX+ORZM9q+98up+mmpqrFjqy3 gUyyg+Nn9uTpaYlpXLTAMIAUkYEywMmMcYSJk159qWeqj5Rohd89iSWVt zgegjLtIMxLvT86BLvg1x229YKuHC5iwekIrhIdhn7tzzniX+lmoZTWDZ o9S86wU6eR+ArwoldLzPGegrNJJB4i/1KYS5Gf+BSB+19IcVP5AE/fZHu 18gABjUIyJg1lUWeoQlCj7jphouklLtmZBw2/7Aw4jsfptn2Qw2+XJg6l A==; X-IronPort-AV: E=McAfee;i="6500,9779,10586"; a="350662836" X-IronPort-AV: E=Sophos;i="5.96,317,1665471600"; d="scan'208";a="350662836" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2023 07:03:37 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10586"; a="687955288" X-IronPort-AV: E=Sophos;i="5.96,317,1665471600"; d="scan'208";a="687955288" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.55]) by orsmga008.jf.intel.com with SMTP; 11 Jan 2023 07:03:31 -0800 Received: by stinkbox (sSMTP sendmail emulation); Wed, 11 Jan 2023 17:03:30 +0200 Date: Wed, 11 Jan 2023 17:03:30 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Brian Norris , Heiko =?iso-8859-1?Q?St=FCbner?= , Sean Paul , Michel =?iso-8859-1?Q?D=E4nzer?= , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Sandy Huang , linux-rockchip@lists.infradead.org, stable@vger.kernel.org Subject: Re: [PATCH 1/2] drm/atomic: Allow vblank-enabled + self-refresh "disable" Message-ID: References: <20230105174001.1.I3904f697863649eb1be540ecca147a66e42bfad7@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Patchwork-Hint: comment Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 06, 2023 at 09:30:56PM +0100, Daniel Vetter wrote: > On Fri, Jan 06, 2023 at 11:33:06AM -0800, Brian Norris wrote: > > On Fri, Jan 06, 2023 at 07:17:53PM +0100, Daniel Vetter wrote: > > > - fake vblanks with hrtimer, because on most hw when you turn off the crtc > > > the vblanks are also turned off, and so your compositor would still > > > hang. The vblank machinery already has all the code to make this happen > > > (and if it's not all, then i915 psr code should have it). > > > > Is a timer better than an interrupt? I'm pretty sure the vblank > > interrupts still can fire on Rockchip CRTC (VOP) (see also the other > > branch of this thread), so this isn't really necessary. (IGT vblank > > tests pass without hanging.) Unless you simply prefer a fake timer for > > some reason. > > > > Also, I still haven't found that fake timer machinery, but maybe I just > > don't know what I'm looking for. > > I ... didn't find it either. I'm honestly not sure whether this works for > intel, or whether we do something silly like disable self-refresh when a > vblank interrupt is pending :-/ Intel hardware doesn't enter PSR while the vblank interrupt is enabled. -- Ville Syrjälä Intel