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

[Maíra Canal]

Hi Phil,

On 4/14/24 15:43, Phil Elwell wrote:
> Hello all,
> 
> On Fri, 12 Apr 2024 at 18:17, Stefan Wahren <wahrenst at gmx.net> wrote:
>>
>> Hi Maíra,
>>
>> [add Phil & Dave]
>>
>> Am 12.04.24 um 15:25 schrieb Maíra Canal:
>>> 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.
>> thanks for trying to improve the combination Raspberry Pi OS + Mainline
>> Kernel. I think i'm able to reproduce the issue with Raspberry Pi 3 B +
>> on Buster.
> 
> Buster? We launched Buster with 4.19 and ended on 5.10. We've moved
> onto Bookworm now. A lot has changed in that time...
> 
>>  From the kernel side everything looks good:
>>
>> [   11.054833] vc4-drm soc:gpu: bound 3f902000.hdmi (ops vc4_hdmi_ops [vc4])
>> [   11.055118] vc4-drm soc:gpu: bound 3f806000.vec (ops vc4_vec_ops [vc4])
>> [   11.055340] vc4-drm soc:gpu: bound 3f004000.txp (ops vc4_txp_ops [vc4])
>> [   11.055521] vc4-drm soc:gpu: bound 3f206000.pixelvalve (ops
>> vc4_crtc_ops [vc4])
>> [   11.055695] vc4-drm soc:gpu: bound 3f207000.pixelvalve (ops
>> vc4_crtc_ops [vc4])
>> [   11.055874] vc4-drm soc:gpu: bound 3f807000.pixelvalve (ops
>> vc4_crtc_ops [vc4])
>> [   11.056020] vc4-drm soc:gpu: bound 3fc00000.v3d (ops vc4_v3d_ops [vc4])
>> [   11.063277] Bluetooth: hci0: BCM4345C0
>> 'brcm/BCM4345C0.raspberrypi,3-model-b-plus.hcd' Patch
>> [   11.070466] [drm] Initialized vc4 0.0.0 20140616 for soc:gpu on minor 0
>> [   11.174803] Console: switching to colour frame buffer device 240x75
>> [   11.205125] vc4-drm soc:gpu: [drm] fb0: vc4drmfb frame buffer device
>>
>> But 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. If i run strace on this command it seems to check
>> for /proc/device-tree/soc/v3d at 7ec00000/status which doesn't exists in
>> the Mainline device tree.
>>
>> Maybe there is a chance to improve the userspace tool?
> 
> ...such as the raspi-config tool, which now always succeeds for is_kms.
> 

I'm using Raspberry Pi OS Bulleye with the raspi-config tool on version
20231012~bulleye. I can still reproduce this issue when using a upstream
kernel.

I ran `sudo apt upgrade`, but a new version of the raspi-config tool
didn't appeared.

Best Regards,
- Maíra

> Phil
> 
>>>
>>> Signed-off-by: Maíra Canal <mcanal at igalia.com>
>>> ---
>>>
>>> I decided to add the status property to the `bcm2835-common.dtsi`, but
>>> there are two other options:
>>>
>>> 1. To add the status property to the `bcm2835-rpi-common.dtsi` file
>>> 2. To add the status property to each individual RPi model, e.g.
>>> `bcm2837-rpi-3-b.dts`.
>>>
>>> Let me know which option is more suitable, and if `bcm2835-common.dtsi`
>>> is not the best option, I can send a v2.
>>>
>>> Best Regards,
>>> - Maíra
>>>
>>>    arch/arm/boot/dts/broadcom/bcm2835-common.dtsi | 1 +
>>>    1 file changed, 1 insertion(+)
>>>
>>> diff --git a/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi b/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi
>>> index 9261b67dbee1..851a6bce1939 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 at 7ec00000 {
>>>                        compatible = "brcm,bcm2835-v3d";
>>>                        reg = <0x7ec00000 0x1000>;
>>>                        interrupts = <1 10>;
>>> +                     status = "okay";
>>>                };
>>>
>>>                vc4: gpu {
>>