imx: imx8mm: imx8mm-kontron-n801x-s: does not start work

[Frieder Schrempf]

On 12.01.22 08:16, Heiko Thiery wrote:
> Hi Adam, Hi Frieder,
> 
> Am Di., 11. Jan. 2022 um 20:33 Uhr schrieb Adam Ford <aford173 at gmail.com>:
>>
>> On Tue, Jan 11, 2022 at 1:18 AM Heiko Thiery <heiko.thiery at gmail.com> wrote:
>>>
>>> Hi all,
>>>
>>> I wanted to test the newly introduced kontron-sl-mx8mm_defconfig but
>>> it does not work.
>>>
>>> I already found two converted config options that are missing in that defconfig:
>>>
>>> +CONFIG_SPL_MMC=y
>>> +CONFIG_SPL_SERIAL=y
>>>
>>> With that the output appears but the u-boot hangs when trying to find
>>> the binman node in the dtb.
>>>
>>> --- >8 ----
>>> U-Boot SPL 2022.01-00323-g56915a34d1 (Jan 11 2022 - 08:11:03 +0100)
>>> Kontron SL i.MX8MM (N801X) module, 1 GB RAM detected
>>> Touch controller detected, assuming LVDS panel...
>>> Normal Boot
>>> WDT:   Not starting watchdog at 30280000
>>> Trying to boot from MMC2
>>> NOTICE:  BL31: v2.4(release):v2.4
>>> NOTICE:  BL31: Built : 09:46:16, Jan 10 2022
>>>
>>>
>>> U-Boot 2022.01-00323-g56915a34d1 (Jan 11 2022 - 08:11:03 +0100)
>>>
>>> CPU:   Freescale i.MX8MMQ rev1.0 1600 MHz (running at 1200 MHz)
>>> CPU:   Industrial temperature grade (-40C to 105C) at 47C
>>> Reset cause: POR
>>> Model: Kontron i.MX8MM N801X S LVDS
>>> DRAM:  1 GiB
>>> binman_init failed:-2
>>> initcall sequence 000000007ffcef80 failed at call 000000004021f200 (err=-2)
>>> ### ERROR ### Please RESET the board ###
>>> --- >8 ----
>>>
>>> Does anyone have an idea what goes wrong?
>>
>> I did a diff on your defconfig and compared it to the imx8mm_beacon
>> board, and there are few items that are different, but nothing
>> obvious.  I confirmed the Beacon board does boot.  You might want to
>> compare your defconfig files with other boards to see if you see
>> something.
>>
>> One main difference is that I have only one DTB file integrated into
>> the FIT file, but you have several.  I wonder if that is causing
>> issues.
> 
> Thank you for the hint with the second dtb. It looks like a problem
> with the imx8mm-kontron-n801x-s-u-boot.dtsi file. Since there is an
> automatic detection in the board code what dtb to select in my case
> the second one is selected. This is the
> imx8mm-kontron-n801x-s-lvds.dtb. But for this one *-u-boot.dtsi is not
> included. When doing a copy of the "base" -u-boot.dtsi file that
> matches to the imx8mm-kontron-n801x-s-lvds.dtb name it works. Still
> the question why this worked before. We have to figure out what the
> difference is here compared to the version that was developed and
> worked on 2021.10.

Thanks for investigating this issue!

I can't really tell what went wrong at the moment. Either something has
changed recently or I missed that the second dtb is not working as I was
mostly testing with the first one!?

Adding a imx8mm-kontron-n801x-s-lvds-u-boot.dtsi with an include to
imx8mm-kontron-n801x-s-u-boot.dtsi seems like a proper fix to me.

In the long run it would probably be better to use only one dtb and
apply overlays as needed, anyway. But I haven't looked into that yet.