Re: [PATCH] arm64: dts: amlogic: meson-sm1-odroid: let the SD card be powered down

[Christian Hewitt <christianshewitt@gmail.com>]

> On 8 Oct 2026, at 1:05 am, Igor Velkov <iav@iav.lv> wrote:
> 
> Follow-up to the dropped patch.
> 
> An out-of-tree restart handler [1] power-cycles the card: it drives
> TFLASH_VDD and both tf_io lines low for 100 ms, then releases them and
> the card is powered again. With the SPI flash erased, ODROID-HC4 boots
> from SD after a warm reboot 5/5 on 6.18, 7.2 and 7.3-rc5. Without the
> handler the boot stalls in the ROM or in U-Boot.
> 
> Where should this live upstream: the mmc core on restart, meson-gx-mmc,
> or a board driver like this one?
> 
> [1] https://github.com/armbian/build/blob/main/patch/kernel/archive/meson64-7.3/meson64-reboot-02-port-to-gpiod.patch

I’ve been doing some bring-up work on S4 support with a VIM1S board
and Claude initially suggested a u-boot variant of the same patch [1]
which improved but did not fully resolve the situation. I was also not
able to explain why applying the same change via the Linux device-tree
that u-boot consumes didn’t have the same effect as essentially the
same change in the u-boot dtsi file.

Claude subsequently added a second patch [2] which resulted in 100%
reliable boot. However that allowed me to move forwards with kernel
work and I haven’t yet circled back to u-boot to run an experiment
without the first patch.

[1] https://github.com/chewitt/u-boot/commit/0a3f5693a4ff192eb044fc4c5a434770de053835
[2] https://github.com/chewitt/u-boot/commit/8e663632bc500ee6a83a846bcd3242231c33aa43

As usual both of Claude’s authoritatively worded descriptions sound
convincingly or conveniently good :)

Christian