From patchwork Thu Oct 20 14:23:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 13013588 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 0E27FC433FE for ; Thu, 20 Oct 2022 14:23:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9A4AE10E169; Thu, 20 Oct 2022 14:23:51 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id D350A10F2C5 for ; Thu, 20 Oct 2022 14:23:46 +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 8ADCFD6E; Thu, 20 Oct 2022 07:23:52 -0700 (PDT) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6A8213F67D; Thu, 20 Oct 2022 07:23:45 -0700 (PDT) From: Robin Murphy To: thierry.reding@gmail.com Subject: [PATCH v2] gpu: host1x: Avoid trying to use GART on Tegra20 Date: Thu, 20 Oct 2022 15:23:40 +0100 Message-Id: <39c44dce203112a8dfe279e8e2c4ad164e3cf5e5.1666275461.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.36.1.dirty MIME-Version: 1.0 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: linux-tegra@vger.kernel.org, iommu@lists.linux.dev, Dmitry Osipenko , dri-devel@lists.freedesktop.org, Jon Hunter Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Since commit c7e3ca515e78 ("iommu/tegra: gart: Do not register with bus") quite some time ago, the GART driver has effectively disabled itself to avoid issues with the GPU driver expecting it to work in ways that it doesn't. As of commit 57365a04c921 ("iommu: Move bus setup to IOMMU device registration") that bodge no longer works, but really the GPU driver should be responsible for its own behaviour anyway. Make the workaround explicit. Reported-by: Jon Hunter Suggested-by: Dmitry Osipenko Signed-off-by: Robin Murphy Tested-by: Jon Hunter --- v2: Cover DRM instance too, move into *_wants_iommu() for consistency drivers/gpu/drm/tegra/drm.c | 4 ++++ drivers/gpu/host1x/dev.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c index 6748ec1e0005..a1f909dac89a 100644 --- a/drivers/gpu/drm/tegra/drm.c +++ b/drivers/gpu/drm/tegra/drm.c @@ -1093,6 +1093,10 @@ static bool host1x_drm_wants_iommu(struct host1x_device *dev) struct host1x *host1x = dev_get_drvdata(dev->dev.parent); struct iommu_domain *domain; + /* Our IOMMU usage policy doesn't currently play well with GART */ + if (of_machine_is_compatible("nvidia,tegra20")) + return false; + /* * If the Tegra DRM clients are backed by an IOMMU, push buffers are * likely to be allocated beyond the 32-bit boundary if sufficient diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c index 0cd3f97e7e49..f60ea24db0ec 100644 --- a/drivers/gpu/host1x/dev.c +++ b/drivers/gpu/host1x/dev.c @@ -292,6 +292,10 @@ static void host1x_setup_virtualization_tables(struct host1x *host) static bool host1x_wants_iommu(struct host1x *host1x) { + /* Our IOMMU usage policy doesn't currently play well with GART */ + if (of_machine_is_compatible("nvidia,tegra20")) + return false; + /* * If we support addressing a maximum of 32 bits of physical memory * and if the host1x firewall is enabled, there's no need to enable