[IMX] [DRM]: suspend/resume support

[Fabio Estevam]

On Wed, Jun 19, 2019 at 10:33 AM Pintu Agarwal <pintu.ping at gmail.com> wrote:

> You can think that the version I am using right now is almost 4.9 itself.

"almost 4.9" does not help, sorry.

> Upgrading again to higher kernel version is again difficult, also
> customer does not want it.

dw-hdmi is well supported on i.MX6 with mainline, so you could simply try that.

Try booting 5.1.11 on your custom board with a very minimal dts with
HDMI support.

Then you can test suspend/resume and see if HDMI hangs or not.

> Another approach I tried is, installing hdmi {dw-hdmi.ko,
> dw_hdmi-imx.ko} as a module, just after the resume.
> With this also system hangs during installation of dw_hdmi-imx.ko at
> below location:
>
> imx_drm_driver_load(..)
> |
> |--> component_bind_all(...)
>      |
>      |-> component_bind(ipu)
>          |
>          |
>          ipu_drm_bind(..)
>          |
>          |-> ipu_crtc_init(..)
>              |
>              |-> ipu_plane_irq(..)
>              |
>              | ----> << __HANGS HERE__ >>

I am not able to reproduce this hang. As I mentioned yesterday
suspend/resume is working just fine.

We would be glad to help fixing the hang if you could reproduce it
with a mainline kernel.