imx8mm-evk does not boot kernel 5.16

[Marcel Ziswiler]

Hi Fabio

On Fri, 2022-01-14 at 15:00 -0300, Fabio Estevam wrote:
> Hi,
> 
> I am able to boot Linux 5.15.14 on an imx8mm-evk running U-Boot
> 2022.01 just fine.
> 
> However, if I try to boot a 5.16 kernel, the boot fails in most of the
> attempts (like in 80% of the boots. It does boot completely in some of
> the attempts).
> 
> Starting kernel ...
>  (hangs here)
> 
> Using earlycon I see that it hangs around the imx-sdma driver load:
> [    0.681930] imx-sdma 302c0000.dma-controller: Direct firmware load
> for imx/sdma/sdma-imx7d.bin failed with error -2
> [    0.689628] imx-sdma 302c0000.dma-controller: external firmware not
> found, using ROM firmware
> [    0.689635] imx-sdma 302b0000.dma-controller: external firmware not
> found, using ROM firmware
> 
> Tried to disable the imx-sdma driver and the hang also happens, so it
> is something else that causes the hang.
> 
> If I use U-Boot from NXP the problem does not happen.
> 
> I tried to select the imx8m power domain options:
> 
> --- a/configs/imx8mm_evk_defconfig
> +++ b/configs/imx8mm_evk_defconfig
> @@ -72,6 +72,8 @@ CONFIG_MII=y
>  CONFIG_PINCTRL=y
>  CONFIG_SPL_PINCTRL=y
>  CONFIG_PINCTRL_IMX8M=y
> +CONFIG_POWER_DOMAIN=y
> +CONFIG_IMX8M_POWER_DOMAIN=y
>  CONFIG_DM_PMIC=y
>  CONFIG_SPL_DM_PMIC_PCA9450=y
>  CONFIG_DM_REGULATOR=y
> 
> but it did not help.
> 
> The same behavior is seen with the top of tree U-Boot.
> 
> Does anyone have any ideas as to what is missing?

Strange, remember, I am working on Verdin iMX8M Mini support [1] and run that stuff more or less daily.
However, as you can see in that patch series, I build the imx-sdma driver now as a module just like already
merged for imx_v6_v7_defconfig. As I also do have an imx8mm-evk laying around somewhere I can give that a try
as well. I keep you posted...

[1] https://lore.kernel.org/lkml/20220114141507.395271-1-marcel@ziswiler.com/

> Thanks,
> 
> Fabio Estevam

Cheers

Marcel