Re: ARM iMX6sx board fails to boot with kernel 6.17

[Sergey Organov <sorganov@gmail.com>]

Hi Fabio,

Fabio Estevam <festevam@gmail.com> writes:

> Hi Sergey,
>
> On Tue, Sep 30, 2025 at 12:49 PM Sergey Organov <sorganov@gmail.com> wrote:
>>
>> Hello,
>>
>> I'm looking for help with the following issue.
>>
>> I'm trying to upgrade kernel on my custom iMX6sx board from very old
>> 4.9.146 to resent 6.17. The board has eMMC connected to usdhc4, and
>> u-boot happily starts kernel from eMMC. The kernel boot sequence,
>> however, hangs waiting for root file-system as it doesn't see eMMC.
>
> I tried booting 6.17 on an imx6sx-sdb board and it booted
> successfully:

Now after further investigations of the issue I find that success
a bit surprising.

I've found that my problem is cured by a commit in

https://github.com/nxp-imx/linux-imx

that works-around an issue that looks like imx6sx generic problem, and
should probably cause troubles on imx6sx-sdb board as well, but doesn't?
The commit is:

commit 65cf3a49ab15cdbbede3c97fd6bba731a3cd366f
Author:     Anson Huang <b20788@freescale.com>
AuthorDate: Tue Aug 18 15:53:54 2015 +0800
Commit:     Octavian Purdila <octavian.purdila@nxp.com>
CommitDate: Thu Feb 23 14:21:42 2017 +0200

    MLK-11375-2 ARM: imx: disable cpuidle for imx6sx

    i.MX6SX CPUIdle with ARM core power down has issue
    and cause system hang during kernel boot up, disable
    it for now and will enable it when busfreq driver
    is ready.

Later (by the DAG, not by date) on the same imx_4.9.11_1.0.0_ga
branch at that repo, there is:

commit 816978f83b1d8dd6ce3bd5dd62223dbfdf74bdd3
Author:     Anson Huang <b20788@freescale.com>
AuthorDate: Mon Oct 20 16:16:20 2014 +0800
Commit:     Octavian Purdila <octavian.purdila@nxp.com>
CommitDate: Thu Feb 23 14:21:42 2017 +0200

    MLK-9708 arm: imx: add low power idle support for i.mx6sx
    
that effectively reverts the aforementioned commit while adding a lot of
other stuff. The resulting kernel also boots fine on my hardware.

Curiously enough, neither of these commits are there in the latest
branch lf-6.12.y there (and that kernel hangs on my board as well.)

Provided the latter commit is indeed the right fix for imx6sx support in
the kernel, what's the procedure to get it to the mainstream Linux
kernel?

Thanks,
-- Sergey Organov