Re: imx6 DM_VIDEObroken

[Anatolij Gustschin <agust@denx.de>]

Hey Tim,

On Mon, 27 Sep 2021 17:25:58 -0700
Tim Harvey tharvey@gateworks.com wrote:

> Anatolij,
> 
> Since commit d37618d18d49 ("imx: convert gwventana board to DM_VIDEO")
> video support for IMX6 based Ventana boards has been broken.

Back then I've tested similar DM_VIDEO conversion changes on i.mx6q
nitrogen6q board and on i.mx6d/i.mx6s wandboards, it was okay if
the board configuration uses the video console output during the
boot sequence (i.e. configured to show splash screen or to output
strings on vidconsole).
 
> I find that while the bind function for fsl_imx6q_ipu is called the
> probe never is (ipuv3_video_probe). Do you know why this is?

Is video console output used during the boot? If not, then it
might be the reason. With DM, the devices are probed when a subsystem
actually tries to use them. You can try to trigger probing via
switching to the video console output, i.e.:

 => setenv stdout vidconsole
> 
> I see that with commit 57f065fee2a4 ("video: ipuv3: add DM_VIDEO
> support") you mention that DTS files must include
> 'u-boot,dm-pre-reloc' for soc/ipu nodes to enable driver binding to
> ipu device but I haven't been able to get that to make a difference
> nor have I found a board that does this. You did add those props to
> imx6qdl.dtsi at one point but they are no longer there.

Does your board dts include imx6qdl-u-boot.dtsi ?

The u-boot,dm-pre-reloc properties were moved to this U-Boot specific
dtsi in 7932b1c9fdb73393aa110249c89bd426533c0649
(imx: imx6qdl: dtsi: move U-Boot specific change to u-boot.dtsi)

> There must have been several other IMX6 boards with video support that
> were affected by this so perhaps I'm missing something simple.

I did not test it recently, it looks I'll have to do it before the
new release.

--
Anatolij