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 C8E32C3DA7A for ; Fri, 6 Jan 2023 19:25:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229452AbjAFTZ6 (ORCPT ); Fri, 6 Jan 2023 14:25:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235518AbjAFTZq (ORCPT ); Fri, 6 Jan 2023 14:25:46 -0500 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 651D16CFF2 for ; Fri, 6 Jan 2023 11:25:44 -0800 (PST) Received: by mail-pj1-x102b.google.com with SMTP id m7-20020a17090a730700b00225ebb9cd01so6141445pjk.3 for ; Fri, 06 Jan 2023 11:25:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=uxQq5OsPBQFav8FuAajxIExQ+FkVdz7c0EkTv5l/tRI=; b=LBNZFQBWQjoz3m56JhOuWZSRkZ6sIJyW0+zkls88KNVqx6ueQlB1fEgi//LPGqbeFu 3uzdbxVriLfz6MURcwOgECHpl5gtBtkGKFfV4FAMveAObnIJwuMgM7tdFFtOQDp1nIsc tg6qNQRddwXCNeg7f6GFTM5Fd4jGQ4XejdT0c= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=uxQq5OsPBQFav8FuAajxIExQ+FkVdz7c0EkTv5l/tRI=; b=aSeQffnkOjWcfo46QymwMumetBMyRjOVPCfceMGaUccxaKl1qUcvd+CqFnCOtBNkRU UhqYXn3vgHQDtdkU4aNTqfd8F3f5Cso3mytjgvf384kEVGUPqdSsmwXgHhPh9RlDUJcc YHu655PbMgPgkLT/64Z17x+hjhtxBXxak65Gg9IUxZJotvc1nbqZkHYiuR5bhhgMTxAx YEGp1HmpGWVky0dNvyIUVNN+mNNE793f7/QGSASyp7sI6uMuty0Q3JtkibpuZeCEV4cQ 5zSVuIdgJbQMOwGqBZfX2J9RvGcpU1Z5+mzy7NADjAduuFUwlU0l3J1Y2eFxC24+IULs glMw== X-Gm-Message-State: AFqh2koSUJ4bKZB7gihN1QxCJk+h6P31xfV7OcUqLo7ProWtvgo/nKnO OvVZnk1ueZ/s90AUSgnj82DXXQ== X-Google-Smtp-Source: AMrXdXtejaeCic0Krve8ArpgewZ5oAi0jUSsD4lK/sgmiHZFOc1fwcfCY/4tcCRMstxIA2T2/7YxDw== X-Received: by 2002:a05:6a21:999c:b0:ac:6d11:1ec7 with SMTP id ve28-20020a056a21999c00b000ac6d111ec7mr86001378pzb.17.1673033143884; Fri, 06 Jan 2023 11:25:43 -0800 (PST) Received: from google.com ([2620:15c:9d:2:bc4e:2cc9:68b3:15dc]) by smtp.gmail.com with ESMTPSA id 22-20020a621816000000b00577c5915138sm1442698pfy.128.2023.01.06.11.25.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Jan 2023 11:25:43 -0800 (PST) Date: Fri, 6 Jan 2023 11:25:41 -0800 From: Brian Norris To: 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=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Jan 06, 2023 at 07:20:40PM +0100, Daniel Vetter wrote: > On Fri, Jan 06, 2023 at 10:08:53AM -0800, Brian Norris wrote: > > OK! Then that sounds like it at least ACKs my general idea for this > > series. (Michel and I poked at a few ideas in the thread at [1] and > > landed on approx. this solution, or else a fake/timer like you suggest.) > > Yeah once I stopped looking at this the wrong way round it does make sense > what you're doing. See my other reply, I think with just this series here > the vblanks still stall out? Or does your hw actually keep generating > vblank irq with the display off? I might not be understanding all of the IGT tests that I've run through, but the display is not actually off -- it's sitting on a still frame. But yes, IRQs still come, and I see no hangs. This is also ref'd in patch 2: bed030a49f3e drm/rockchip: Don't fully disable vop on self refresh So, we're not even doing that much to power-down the CRTC/VOP. That's probably why IRQs are still active, contrary to your expectation? NB: this is how Rockchip Chromebooks implemented PSR from essentially day 1. > > On Fri, Jan 06, 2023 at 06:53:49PM +0100, Daniel Vetter wrote: > > > We might need a few more helpers. Also, probably more igt, or is this > > > something igt testing has uncovered? If so, please cite the igt testcase > > > which hits this. > > > > The current patch only fixes a warning that comes when I try to do the > > second patch. The second patch is a direct product of an IGT test > > failure (a few of kms_vblank's subtests), and I linked [1] the KernelCI > > report there. > > Ah yeah that makes sense. Would be good to cite that in this patch too, > because I guess the same kms_vblank tests can also hit this warning here? Well, before this series: no, those tests don't hit this warning. The warning is only uncovered after patch 2. If I do just patch 2, it's super-trivial to hit the warning. You just have to turn the display on and go idle long enough for PSR to activate once. I suppose that can count as "caught by a test", with a little stretch of the imagination. At any rate, I'll improve this description to refer precisely to the "next patch" (as Greg suggested already), and that might involve describing this test case a little. Brian