[IMX] [DRM]: suspend/resume support

[Pintu Agarwal]

On Wed, Jun 19, 2019 at 7:14 PM Fabio Estevam <festevam at gmail.com> wrote:
>
> 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.
>
Okay. I will surely try it on another IMX6 fresh board.
With 5.1.11 you mean the kernel from mainline kernel.org
Or, is there a separate kernel repo for imx6. If yes, please let me know.

> Then you can test suspend/resume and see if HDMI hangs or not.
>
By this suspend/resume, you mean "suspend-to-ram" or "suspend-to-disk" ?

> > 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.
>
This scenario is not with suspend/resume.
This hang is, when we make hdmi as a loadable module (.ko) and trying
to install it after resume.
In this case, suspend/resume will not come into picture. Not sure why
it still hangs.
Do you have any clue for this scenario?