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 35264C433F5 for ; Mon, 2 May 2022 17:04:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 534DD10E27B; Mon, 2 May 2022 17:04:21 +0000 (UTC) Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by gabe.freedesktop.org (Postfix) with ESMTPS id A052810E27B for ; Mon, 2 May 2022 17:04:19 +0000 (UTC) Received: by mail-wr1-x436.google.com with SMTP id k2so20326961wrd.5 for ; Mon, 02 May 2022 10:04:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=IKIkKWLuV1OGwYFULnAsOkM2G0PGs69FkOVI5N/cNnw=; b=E00mffjDjTe6c/+9iDlEB1wdjEcT0U7DrFgxMpBPQJx9s+IQ4i+hMTICCKe1dASuRK vv17Che0ajGuui4mx+K4r1+z9SF2TndTWwcLkPj7BMuHQVSLA/G8SdWC1WOJcaezXcEO b/Tooz0sFb9G1wLn4RiJVFlcskkBXXUmyjKYwz7a9+TwyRGdWnAuwzUf0fCiUkO4ygoB YD8aLEPqcUpn/YjO2ONOe5YijCPdvSc8VQbjgldKdr1xt9IDzvQxyEeVTIAnEu+JSpYf STMZn12f6RylbjtgqkIXpQn6ujutZoG6Wz/zFfehbOoE6scGhaR9O9vV+mvz4mPPLlYt 5d8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=IKIkKWLuV1OGwYFULnAsOkM2G0PGs69FkOVI5N/cNnw=; b=NRd3I+8BI7o+FMiMObE5DGdhlxtW6/9dZhbuFmVlfdjJJes3j8/fAQSf7Kmw3tBuuS 30mcYBDeQQCWpZNsUQhUFYSbBXtFA6D2x6ddf5U0RsL63PQDFOL8L6Y3/3T9erDPV2A7 k+qyV0va5IRH6Be8K0gePCAT+My2vYgieEnKlIwGgqO7YDS0ijM+9AWj8NOtMpZK51Jx 9bMpixvRYzgDUhW3xKg4+YVgFRMGfD4nDgmkpsGD/rqIUnMbxLTkT0Bn6EGw30DsBNUo S587rGEIiK/7XRo75Qbyp7Nt40J8yK/1x4atDwrpdnUhdme0UrG/PJxlHLkpcU3oyMQ0 2SaA== X-Gm-Message-State: AOAM532OM1bPWjD7oYOfTbLWkPy1DIW/z48goAwf0x1TTwb2qobuENmu vUmsohJ96nd3jg4WDFbH6u/5YAe3s/8= X-Google-Smtp-Source: ABdhPJyY68uLuAzWuSiv8NzwPVrip8vAdDKoe4nwXxnPu/iAX4m8EhrXazWqZbj5vHpF7sAHIxdztA== X-Received: by 2002:a5d:5885:0:b0:20c:7048:2951 with SMTP id n5-20020a5d5885000000b0020c70482951mr1354652wrf.28.1651511058007; Mon, 02 May 2022 10:04:18 -0700 (PDT) Received: from orome ([62.96.65.119]) by smtp.gmail.com with ESMTPSA id k8-20020adfc708000000b0020c5253d8easm9375256wrg.54.2022.05.02.10.04.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 May 2022 10:04:16 -0700 (PDT) Date: Mon, 2 May 2022 19:04:13 +0200 From: Thierry Reding To: Cai Huoqing Subject: Re: [PATCH v2 0/4] drm/nvdla: Add driver support for NVDLA Message-ID: References: <20220426060808.78225-1-cai.huoqing@linux.dev> <20220429032810.GA10104@chq-T47> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="xESg3apyTC1nCRXH" Content-Disposition: inline In-Reply-To: <20220429032810.GA10104@chq-T47> User-Agent: Mutt/2.2.1 (c8109e14) (2022-02-19) 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: Mikko Perttunen , David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Sumit Semwal , linaro-mm-sig@lists.linaro.org, Thomas Zimmermann , linux-tegra@vger.kernel.org, Jon Hunter , Christian =?utf-8?B?S8O2bmln?= , linux-media@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --xESg3apyTC1nCRXH Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Apr 29, 2022 at 11:28:10AM +0800, Cai Huoqing wrote: > On 28 4=E6=9C=88 22 18:56:07, Mikko Perttunen wrote: > > On 4/28/22 17:10, Thierry Reding wrote: > > > On Tue, Apr 26, 2022 at 02:07:57PM +0800, Cai Huoqing wrote: > > > > The NVIDIA Deep Learning Accelerator (NVDLA) is an open source IP > > > > which is integrated into NVIDIA Jetson AGX Xavier, > > > > so add driver support for this accelerator." > > >=20 > > > Hi, > > >=20 > > > nice to see this work going on. For subsequent revisions, can you ple= ase > > > also Cc the Tegra mailing list (linux-tegra@vger.kernel.org) as well = as > > > the Tegra platform maintainers (that's Jon Hunter and myself). This w= ill > > > make sure that more people with an interest in this will see your wor= k. > > > Not everyone follows dri-devel, linaro-mm-sig or linux-media. > > >=20 > > > Thanks, > > > Thierry > >=20 > > From a quick glance it looks like this driver pokes DLA hardware direct= ly > > which is not the intended programming model on Tegra hardware (there are > > Falcon microcontrollers that offload task scheduling and synchronization > > from the CPU). The hardware is also behind the Host1x bus so a simple > > platform device is not sufficient. > >=20 > > Was this driver developed against some platform with OpenDLA hardware (= i.e. > > not Tegra)? > >=20 > > If so, we'd need to verify if the hardware matches the hardware in Tegr= a194. > > Also, this driver may not be ideal for Tegra platforms since we would l= ack > > the hardware scheduling and synchronization facilities. It is likely > > necessary to have separate drivers for OpenDLA and Tegra's DLA integrat= ion. > >=20 > > Thanks, > > Mikko > >=20 > Tegra DLA seems to work with a slave coprocessor, the host driver just > impelement message queue, share buffer, notification... The hardware > detail of DLA maybe in the slave driver(not linux OS?). >=20 > Sure, This driver just support for the SOCs or FPGAs that OPENDLA > inside. I will change this kind of description "integrated into NVIDIA Je= tson AGX Xavier" > this driver dont support for Tegra directly. Yes, I think it would be good to make it clear that this is not going to work with the Tegra instantiations so that people don't get confused. I think it would be ideal, though, if we could reuse as much of this driver as possible to work with other instantiations. The only reference to OpenDLA that I can find and which seems somehow relevant to this is here: https://github.com/SCLUO/ITRI-OpenDLA Is that the version that you're using? Or is the version that you're using at least compatible with that one? Apart from that and the Tegra instantiations, are you aware of any other derivatives that we need to account for? I'm worried that this might fragment to the point where it becomes unmaintainable in upstream Linux. Even if this doesn't concern the Tegra instantiation, I think most of my other comments remain valid. Things like global variables will get in the way of multiple FPGA instantiations as well, for example. You will also need to provide the device tree bindings for the particular instantiation that you're working on. Typically this would be identified by a vendor-specific compatible string for your particular board, but if it stems from a "canonical" FPGA mapping, matching on that compatible string might also be an option. In either case, when you send out the DT bindings, please include the devicetree@vger.kernel.org mailing list so that they can be properly reviewed. Thierry --xESg3apyTC1nCRXH Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAmJwDwoACgkQ3SOs138+ s6HQBA/9G4mT1YRxO1XmbGtYRMlb5WwgJE5DE02upNSHm7Ixb2KSRxQqcdLPG/rQ ip5zcasTrh9hLKISslL9+mRphslV8obFPSF9tDhQ/SINiIRM/9CYvI4vkr/qe38t C6GU4tlQwn/IJIy1i4jaDVxdFEtQzXEAucfG1lLee1L46jYUpykk3cTKFCZM8xND HTrWnKdCUsjb9it08g68ItVxkq2v5lG2HKT+j4LJeEA82i4iS34/H42QOyQ7yQi9 0CsRDMq/BC7Nu8bSCKzwMAp6FiO9ZSXBPb5Bvpy1gbZRKMX0OvQe2u0/wk2DI0zG G70ioJZUh8lq7Dtx6TnFTaYskxKFipHfni4oBOMXD4GQJ9YPlPG5NMNTDPLvL+Co OqwgDr3EFKee6efZwsJbzYF+2sculK4syW9OHZDvP8RuhqW2qCiWBBQxqj9SY/hB LJ33BUv7iCer3fpSORrmmT2rNRzCw0xqiOWniofQTdKZUDtphrjwxW9wT+FbnFNw /mrXZGsB8UY8sKQyhR3FDL74g6QYb9wrpq9mJ4jKD/Py3Yd00v00GjgeDHmb7V/d weu2Nrx1NG83vW4rBqGd4qnOZbMQtEesVgaa3SYmH5lyJSzAnCB9QT5PPR3xL8o3 96I0sU2UqMHqWjCMqKFLD8886Oovi3Jo4uuXONTL95ZIDoScJaw= =Kefv -----END PGP SIGNATURE----- --xESg3apyTC1nCRXH--