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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 7B1F0C33CA1 for ; Thu, 9 Jan 2020 13:29:45 +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 58A5320661 for ; Thu, 9 Jan 2020 13:29:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 58A5320661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C16556E40B; Thu, 9 Jan 2020 13:29:44 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id DE7ED6E40B for ; Thu, 9 Jan 2020 13:29:42 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6179E31B; Thu, 9 Jan 2020 05:29:42 -0800 (PST) Received: from arm.com (e112269-lin.cambridge.arm.com [10.1.194.52]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 65F263F534; Thu, 9 Jan 2020 05:29:40 -0800 (PST) Date: Thu, 9 Jan 2020 13:29:35 +0000 From: Steven Price To: Robin Murphy Subject: Re: [PATCH v2 0/7] Add dts for mt8183 GPU (and misc panfrost patches) Message-ID: <20200109132934.GA6198@arm.com> References: <20200108052337.65916-1-drinkcat@chromium.org> <79fe7055-c11b-c9f6-64e5-48e3d5687dfe@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , "devicetree@vger.kernel.org" , Nicolas Boichat , Tomeu Vizoso , David Airlie , Mark Brown , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , Liam Girdwood , Rob Herring , "linux-mediatek@lists.infradead.org" , Alyssa Rosenzweig , "hsinyi@chromium.org" , Matthias Brugger , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Jan 09, 2020 at 01:10:33PM +0000, Robin Murphy wrote: > On 09/01/2020 12:01 pm, Steven Price wrote: > > On 08/01/2020 05:23, Nicolas Boichat wrote: > >> Hi! > >> > >> Sorry for the long delay since = > >> https://patchwork.kernel.org/patch/11132381/, > >> finally got around to give this a real try. > >> > >> The main purpose of this series is to upstream the dts change and the = > >> binding > >> document, but I wanted to see how far I could probe the GPU, to check = > >> that the > >> binding is indeed correct. The rest of the patches are = > >> RFC/work-in-progress, but > >> I think some of them could already be picked up. > >> > >> So this is tested on MT8183 with a chromeos-4.19 kernel, and a ton of > >> backports to get the latest panfrost driver (I should probably try on > >> linux-next at some point but this was the path of least resistance). > >> > >> I tested it as a module as it's more challenging (originally probing = > >> would > >> work built-in, on boot, but not as a module, as I didn't have the power > >> domain changes, and all power domains are on by default during boot). > >> > >> Probing logs looks like this, currently: > >> [=A0 221.867726] panfrost 13040000.gpu: clock rate =3D 511999970 > >> [=A0 221.867929] panfrost 13040000.gpu: Linked as a consumer to = > >> regulator.14 > >> [=A0 221.868600] panfrost 13040000.gpu: Linked as a consumer to = > >> regulator.31 > >> [=A0 221.870586] panfrost 13040000.gpu: Linked as a consumer to = > >> genpd:0:13040000.gpu > >> [=A0 221.871492] panfrost 13040000.gpu: Linked as a consumer to = > >> genpd:1:13040000.gpu > >> [=A0 221.871866] panfrost 13040000.gpu: Linked as a consumer to = > >> genpd:2:13040000.gpu > >> [=A0 221.872427] panfrost 13040000.gpu: mali-g72 id 0x6221 major 0x0 = > >> minor 0x3 status 0x0 > >> [=A0 221.872439] panfrost 13040000.gpu: features: 00000000,13de77ff, = > >> issues: 00000000,00000400 > >> [=A0 221.872445] panfrost 13040000.gpu: Features: L2:0x07120206 = > >> Shader:0x00000000 Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xff JS:0= x7 > >> [=A0 221.872449] panfrost 13040000.gpu: shader_present=3D0x7 l2_presen= t=3D0x1 > >> [=A0 221.873526] panfrost 13040000.gpu: error powering up gpu stack > >> [=A0 221.878088] [drm] Initialized panfrost 1.1.0 20180908 for = > >> 13040000.gpu on minor 2 > >> [=A0 221.940817] panfrost 13040000.gpu: error powering up gpu stack > >> [=A0 222.018233] panfrost 13040000.gpu: error powering up gpu stack > >> (repeated) > > = > > It's interesting that it's only the stack that is failing. In hardware = > > there's a dependency: L2->stack->shader - so in theory the shader cores = > > shouldn't be able to power up either. There are some known hardware bug= s = > > here though[1]: > > = > > =A0=A0=A0=A0MODULE_PARM_DESC(corestack_driver_control, > > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 "Let the driver power on/off the GPU= core stack = > > independently " > > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 "without involving the Power Domain = Controller. This should " > > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 "only be enabled on platforms for wh= ich integration of the = > > PDC " > > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 "to the Mali GPU is known to be prob= lematic."); > > = > > [1] = > > https://github.com/ianmacd/d2s/blob/master/drivers/gpu/arm/b_r16p0/back= end/gpu/mali_kbase_pm_driver.c#L57 = > > = > > = > > It might be worth just dropping the code for powering up/down stacks an= d = > > let the GPU's own dependency management handle it. > = > FWIW I remember digging into that same message a while back (although = > I've forgotten which particular GPU I was playing with at the time), and = > concluded that the STACK_PWRON/STACK_READY registers might just not be = > implemented on some GPUs, They are indeed not implemented on some GPUs. Specifically none of the Midgard GPUs. I believe G71 also doesn't have it. However the register addresses were picked so that on these older GPUs they should read-as-zero and write-ignore so this shouldn't actually cause any problems. > and/or this easy-to-overlook register bit = > could be some kind of enable for the functionality: > = > https://github.com/ianmacd/d2s/blob/master/drivers/gpu/arm/b_r16p0/backen= d/gpu/mali_kbase_pm_driver.c#L1631 > = > Since even in kbase this is all behind an 'expert' config option, I'm = > inclined to agree that just dropping it from panfrost unless and until = > it proves necessary is probably preferable to adding more logic and = > inscrutable register-magic. Indeed - I'll post a patch removing it. Thanks, Steve > Robin. > = > > = > > Steve > > = > >> > >> So the GPU is probed, but there's an issue when powering up the STACK, = > >> not > >> quite sure why, I'll try to have a deeper look, at some point. > >> > >> Thanks! > >> > >> Nicolas > >> > >> v2: > >> =A0 - Use sram instead of mali_sram as SRAM supply name. > >> =A0 - Rename mali@ to gpu@. > >> =A0 - Add dt-bindings changes > >> =A0 - Stacking patches after the device tree change that allow basic > >> =A0=A0=A0 probing (still incomplete and broken). > >> > >> Nicolas Boichat (7): > >> =A0=A0 dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183 > >> =A0=A0 arm64: dts: mt8183: Add node for the Mali GPU > >> =A0=A0 drm/panfrost: Improve error reporting in panfrost_gpu_power_on > >> =A0=A0 drm/panfrost: Add support for a second regulator for the GPU > >> =A0=A0 drm/panfrost: Add support for multiple power domain support > >> =A0=A0 RFC: drm/panfrost: Add bifrost compatible string > >> =A0=A0 RFC: drm/panfrost: devfreq: Add support for 2 regulators > >> > >> =A0 .../bindings/gpu/arm,mali-bifrost.yaml=A0=A0=A0=A0=A0=A0=A0 |=A0 2= 0 ++++ > >> =A0 arch/arm64/boot/dts/mediatek/mt8183-evb.dts=A0=A0 |=A0=A0 7 ++ > >> =A0 arch/arm64/boot/dts/mediatek/mt8183.dtsi=A0=A0=A0=A0=A0 | 104 ++++= +++++++++++++ > >> =A0 drivers/gpu/drm/panfrost/panfrost_devfreq.c=A0=A0 |=A0 18 +++ > >> =A0 drivers/gpu/drm/panfrost/panfrost_device.c=A0=A0=A0 | 108 ++++++++= ++++++++-- > >> =A0 drivers/gpu/drm/panfrost/panfrost_device.h=A0=A0=A0 |=A0=A0 7 ++ > >> =A0 drivers/gpu/drm/panfrost/panfrost_drv.c=A0=A0=A0=A0=A0=A0 |=A0=A0 = 1 + > >> =A0 drivers/gpu/drm/panfrost/panfrost_gpu.c=A0=A0=A0=A0=A0=A0 |=A0 15 = ++- > >> =A0 8 files changed, 267 insertions(+), 13 deletions(-) > >> > > = > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel