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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_SANE_2 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 9BF69C4338F for ; Mon, 26 Jul 2021 10:27:12 +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 5CB4560F22 for ; Mon, 26 Jul 2021 10:27:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5CB4560F22 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DE3A46E863; Mon, 26 Jul 2021 10:27:11 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by gabe.freedesktop.org (Postfix) with ESMTPS id 264426E863 for ; Mon, 26 Jul 2021 10:27:11 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: bbrezillon) with ESMTPSA id 71D481F4285E Date: Mon, 26 Jul 2021 12:27:06 +0200 From: Boris Brezillon To: Christian =?UTF-8?B?S8O2bmln?= Subject: Re: [PATCH v4 5/7] drm/panfrost: Add a new ioctl to submit batches Message-ID: <20210726122706.7fb3a8d5@collabora.com> In-Reply-To: <1fe2d843-041d-40f6-b552-91f159487495@gmail.com> References: <20210705082950.3573841-1-boris.brezillon@collabora.com> <20210705082950.3573841-6-boris.brezillon@collabora.com> <1fe2d843-041d-40f6-b552-91f159487495@gmail.com> Organization: Collabora X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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: Jason Ekstrand , Tomeu Vizoso , dri-devel@lists.freedesktop.org, Steven Price , Rob Herring , Alyssa Rosenzweig , Robin Murphy Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, 8 Jul 2021 14:10:45 +0200 Christian K=C3=B6nig wrote: > >> --- a/drivers/gpu/drm/panfrost/panfrost_job.c > >> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c > >> @@ -254,6 +254,9 @@ static int panfrost_acquire_object_fences(struct p= anfrost_job *job) > >> return ret; > >> } > >> =20 > >> + if (job->bo_flags[i] & PANFROST_BO_REF_NO_IMPLICIT_DEP) > >> + continue; =20 > > This breaks dma_resv rules. I'll send out patch set fixing this pattern= in > > other drivers, I'll ping you on that for what you need to change. Should > > go out today or so. I guess you're talking about [1]. TBH, I don't quite see the point of exposing a 'no-implicit' flag if we end up forcing this implicit dep anyway, but I'm probably missing something. >=20 > I'm really wondering if the behavior that the exclusive fences replaces=20 > all the shared fences was such a good idea. Is that what's done in [1], or are you talking about a different patchset/approach? >=20 > It just allows drivers to mess up things in a way which can be easily=20 > used to compromise the system. I must admit I'm a bit lost, so I'm tempted to drop that flag for now :-). [1]https://patchwork.freedesktop.org/patch/443711/?series=3D92334&rev=3D3