[Mesa-dev] imx/etnaviv: loader_open_render_node() fails

[Emil Velikov]

Hi Lukas,

Adding the etnaviv ML - people in there may have some tips.

On 6 September 2018 at 15:43, Lukas F. Hartmann <lukas at mntmn.com> wrote:
> Hi,
>
> I've updated to and rebuilt the latest git versions of linux, drm, mesa
> and kmscube on an imx6qp system. I tried both with etnaviv as a module
> and compiled into the kernel (no difference).
>
> Mesa no longer picks up etnaviv for GL rendering, but always reverts to
> softpipe. A bit of debugging revealed that the following codepath fails:
>
> imx_drm_screen_create -> loader_open_render_node("etnaviv") ->
> drmGetDevices2 -> drmProcessPlatformDevice(... "/dev/dri/renderD128") ->
> drmParsePlatformBusInfo -> sysfs_uevent_get
>
> The latter function opens /sys/dev/char/226:128/device/uevent and looks
> for OF_FULLNAME, but this key is not present on my system. The node
> contains only:
>
> DRIVER=etnaviv
> MODALIAS=platform:etnaviv
>
> Whereas /sys/dev/char/226:0/device/uevent contains:
>
> DRIVER=imx-drm
> OF_NAME=display-subsystem
> OF_FULLNAME=/display-subsystem
> OF_COMPATIBLE_0=fsl,imx-display-subsystem
> OF_COMPATIBLE_N=1
>
> Which is not the render node.
>
> According to https://patchwork.kernel.org/patch/9487631/#19940985 there
> should be more lines (device tree related?) in the uevent file for the
> render node, and I wonder why they don't exist.
>
Have you considered checking other kernels?

AFAICT entries like that should not just disappear from the uevent file.
My personal, slightly biased, opinion is to track down what broke in
kernel land.

HTH
Emil