From patchwork Sun Jul  9 16:36:14 2017
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Subject: ARM: tegra: Register host1x node with iommu binding on tegra124
From: Paul Kocialkowski <contact@paulk.fr>
X-Patchwork-Id: 9831825
Message-Id: <20170709163614.6746-1-contact@paulk.fr>
To: linux-arm-kernel@lists.infradead.org, linux-tegra@vger.kernel.org,
 linux-kernel@vger.kernel.org
Cc: Thierry Reding <thierry.reding@gmail.com>,
 Stephen Warren <swarren@wwwdotorg.org>,
 Mikko Perttunen <mperttunen@nvidia.com>,
 Paul Kocialkowski <contact@paulk.fr>, 
 Jonathan Hunter <jonathanh@nvidia.com>
Date: Sun,  9 Jul 2017 19:36:14 +0300
 
This registers the host1x node with the SMMU (as HC swgroup) to allow
the host1x code to attach to it. It avoid failing the probe sequence,
which resulted in the tegra drm driver not probing and thus nothing
being displayed on-screen.
 
Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
---
 arch/arm/boot/dts/tegra124.dtsi | 1 +
 1 file changed, 1 insertion(+)
 
diff --git a/arch/arm/boot/dts/tegra124.dtsi b/arch/arm/boot/dts/tegra124.dtsi
index 187a36c6d0fc..b3b89befffeb 100644
--- a/arch/arm/boot/dts/tegra124.dtsi
+++ b/arch/arm/boot/dts/tegra124.dtsi
@@ -85,6 +85,7 @@
 		clocks = <&tegra_car TEGRA124_CLK_HOST1X>;
 		resets = <&tegra_car 28>;
 		reset-names = "host1x";
+		iommus = <&mc TEGRA_SWGROUP_HC>;
 
 		#address-cells = <2>;
 		#size-cells = <2>;
From patchwork Mon Jul 10 19:33:05 2017
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Subject: gpu: host1x: Free the IOMMU domain when there is no device to attach
From: Paul Kocialkowski <contact@paulk.fr>
X-Patchwork-Id: 9833721
Message-Id: <20170710193305.5987-1-contact@paulk.fr>
To: linux-arm-kernel@lists.infradead.org, linux-tegra@vger.kernel.org,
 linux-kernel@vger.kernel.org
Cc: Thierry Reding <thierry.reding@gmail.com>,
 Stephen Warren <swarren@wwwdotorg.org>,
 Mikko Perttunen <mperttunen@nvidia.com>,
 Paul Kocialkowski <contact@paulk.fr>, 
 Jonathan Hunter <jonathanh@nvidia.com>
Date: Mon, 10 Jul 2017 21:33:05 +0200
 
When there is no device to attach to the IOMMU domain, as may be the
case when the device-tree does not contain the proper iommu node, it is
best to keep going without IOMMU support rather than failing.
This allows the driver to probe and function instead of taking down
all of the tegra drm driver, leading to missing display support.
 
Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/gpu/host1x/dev.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
 
diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index ac65f52850a6..f296738d0de8 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -186,8 +186,13 @@ static int host1x_probe(struct platform_device *pdev)
 			return -ENOMEM;
 
 		err = iommu_attach_device(host->domain, &pdev->dev);
-		if (err)
+		if (err == -ENODEV) {
+			iommu_domain_free(host->domain);
+			host->domain = NULL;
+			goto iommu_skip;
+		} else if (err) {
 			goto fail_free_domain;
+		}
 
 		geometry = &host->domain->geometry;
 
@@ -198,6 +203,7 @@ static int host1x_probe(struct platform_device *pdev)
 		host->iova_end = geometry->aperture_end;
 	}
 
+iommu_skip:
 	err = host1x_channel_list_init(host);
 	if (err) {
 		dev_err(&pdev->dev, "failed to initialize channel list\n");