Re: [PATCH v2] ARM: dts: bcm2835: Enable 3D rendering through V3D

Maíra Canal <mcanal@xxxxxxxxxx> · Mon, 15 Apr 2024 22:02:30 -0300

On 4/15/24 13:54, Andre Przywara wrote:
On Mon, 15 Apr 2024 13:00:39 -0300
Maíra Canal <mcanal@xxxxxxxxxx> wrote:

Hi,

RPi 0-3 is packed with a GPU that provides 3D rendering capabilities to
the RPi. Currently, the downstream kernel uses an overlay to enable the
GPU and use GPU hardware acceleration. When deploying a mainline kernel
to the RPi 0-3, we end up without any GPU hardware acceleration
(essentially, we can't use the OpenGL driver).

Therefore, enable the V3D core for the RPi 0-3 in the mainline kernel.

So I think Krzysztof's initial comment still stands: What does that patch
actually change? If I build those DTBs as of now, none of them has a
status property in the v3d node. Which means it's enabled:
https://github.com/devicetree-org/devicetree-specification/blob/main/source/chapter2-devicetree-basics.rst#status
So adding an explicit 'status = "okay";' doesn't make a difference.

What do I miss here?

As mentioned by Stefan in the last version, in Raspberry Pi OS, there is
a systemd script which is trying to check for the V3D driver (/usr/lib
/systemd/scripts/gldriver_test.sh). Within the first check, "raspi-
config nonint is_kms" is called, which always seems to fail. What 
"raspi-config" does is check if 
/proc/device-tree/soc/v3d@7ec00000/status is equal to "okay". As 
/proc/device-tree/soc/v3d@7ec00000/status doesn't exists, it returns false.

I'll send if I can improve the userspace tool by just checking if the
folder /proc/device-tree/soc/v3d@7ec00000/ exists.

Thanks for the explanation!

Best Regards,
- Maíra


Cheers,
Andre

Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
---

v1 -> v2: https://lore.kernel.org/dri-devel/41694292-af1f-4760-a7b6-101ed5dd6f9d@xxxxxxx/T/

* As mentioned by Krzysztof, enabling should be done in last place of
	override/extend. Therefore, I'm disabling V3D in the common dtsi
	and enabling in the last place of extend, i.e. the RPi DTS files.

  arch/arm/boot/dts/broadcom/bcm2835-common.dtsi      | 1 +
  arch/arm/boot/dts/broadcom/bcm2835-rpi-a-plus.dts   | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2835-rpi-a.dts        | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2835-rpi-b-plus.dts   | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2835-rpi-b-rev2.dts   | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2835-rpi-b.dts        | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2835-rpi-cm1-io1.dts  | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2835-rpi-zero-w.dts   | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2835-rpi-zero.dts     | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2836-rpi-2-b.dts      | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2837-rpi-3-a-plus.dts | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b-plus.dts | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b.dts      | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2837-rpi-cm3-io3.dts  | 4 ++++
  arch/arm/boot/dts/broadcom/bcm2837-rpi-zero-2-w.dts | 4 ++++
  15 files changed, 57 insertions(+)

diff --git a/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi b/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi
index 9261b67dbee1..69e34831de51 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi
+++ b/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi
@@ -139,6 +139,7 @@ v3d: v3d@7ec00000 {
  			compatible = "brcm,bcm2835-v3d";
  			reg = <0x7ec00000 0x1000>;
  			interrupts = <1 10>;
+			status = "disabled";
  		};
  
  		vc4: gpu {
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-a-plus.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-a-plus.dts
index 069b48272aa5..495ab1dfd2ce 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-a-plus.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-a-plus.dts
@@ -128,3 +128,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-a.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-a.dts
index 2726c00431e8..4634d88ce3af 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-a.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-a.dts
@@ -121,3 +121,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-plus.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-plus.dts
index c57b999a4520..45fa0f6851fc 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-plus.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-plus.dts
@@ -130,3 +130,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-rev2.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-rev2.dts
index ae6d3a9586ab..c1dac5d704aa 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-rev2.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-b-rev2.dts
@@ -121,3 +121,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-b.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-b.dts
index 72764be75a79..72ca31f2a7d6 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-b.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-b.dts
@@ -115,3 +115,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-cm1-io1.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-cm1-io1.dts
index 3f9d198ac3ab..881a07d2f28f 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-cm1-io1.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-cm1-io1.dts
@@ -95,3 +95,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero-w.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero-w.dts
index 1f0b163e400c..1c7324067442 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero-w.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero-w.dts
@@ -134,6 +134,10 @@ &uart1 {
  	status = "okay";
  };
  
+&v3d {
+	status = "okay";
+};
+
  &wifi_pwrseq {
  	reset-gpios = <&gpio 41 GPIO_ACTIVE_LOW>;
  };
diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero.dts b/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero.dts
index 539c19c10946..1568ddc78f22 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi-zero.dts
@@ -117,3 +117,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2836-rpi-2-b.dts b/arch/arm/boot/dts/broadcom/bcm2836-rpi-2-b.dts
index 79918033750e..8fab6293d1c7 100644
--- a/arch/arm/boot/dts/broadcom/bcm2836-rpi-2-b.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2836-rpi-2-b.dts
@@ -129,3 +129,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-a-plus.dts b/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-a-plus.dts
index 3548306dfbcb..dc45b56054c7 100644
--- a/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-a-plus.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-a-plus.dts
@@ -156,3 +156,7 @@ &uart1 {
  	pinctrl-0 = <&uart1_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b-plus.dts b/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b-plus.dts
index 2f1800cbc522..ce3a9f7ff529 100644
--- a/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b-plus.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b-plus.dts
@@ -161,3 +161,7 @@ &uart1 {
  &wifi_pwrseq {
  	reset-gpios = <&expgpio 1 GPIO_ACTIVE_LOW>;
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b.dts b/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b.dts
index 61270340075c..e398546d105b 100644
--- a/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2837-rpi-3-b.dts
@@ -149,6 +149,10 @@ &sdhost {
  	bus-width = <4>;
  };
  
+&v3d {
+	status = "okay";
+};
+
  &wifi_pwrseq {
  	reset-gpios = <&expgpio 1 GPIO_ACTIVE_LOW>;
  };
diff --git a/arch/arm/boot/dts/broadcom/bcm2837-rpi-cm3-io3.dts b/arch/arm/boot/dts/broadcom/bcm2837-rpi-cm3-io3.dts
index 72d26d130efa..50471ada79b3 100644
--- a/arch/arm/boot/dts/broadcom/bcm2837-rpi-cm3-io3.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2837-rpi-cm3-io3.dts
@@ -94,3 +94,7 @@ &uart0 {
  	pinctrl-0 = <&uart0_gpio14>;
  	status = "okay";
  };
+
+&v3d {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/broadcom/bcm2837-rpi-zero-2-w.dts b/arch/arm/boot/dts/broadcom/bcm2837-rpi-zero-2-w.dts
index 85cf594724ef..876f697e7300 100644
--- a/arch/arm/boot/dts/broadcom/bcm2837-rpi-zero-2-w.dts
+++ b/arch/arm/boot/dts/broadcom/bcm2837-rpi-zero-2-w.dts
@@ -132,6 +132,10 @@ &uart1 {
  	status = "okay";
  };
  
+&v3d {
+	status = "okay";
+};
+
  &wifi_pwrseq {
  	reset-gpios = <&gpio 41 GPIO_ACTIVE_LOW>;
  };








