Re: [PATCH] arm64: dts: ti: k3-am62a7-sk: Disable mmc Schmitt Trigger

["Sverdlin, Alexander" <alexander.sverdlin@siemens.com>]

Hi Judith,

On Wed, 2026-02-04 at 20:03 -0600, Judith Mendez wrote:
> > > > > Can you please run a quick tap sweep on MMC1 and MMC0 interfaces like
> > > > > so? https://gist.github.com/jmenti/f4a73a8323e44bf717c6d2c528c499ca
> > > > > 
> > > > > This will give me an idea if whether we should be talking about
> > > > > revisiting characterization with ST_ENA=1.

I wanted to apply your patch and test on our HW, but I have some doubts, if
the patch maybe missing something:

- am654_sdhci_write_otapdly() turns out to be unused in any upstream U-Boot version
- new "omap" variable in am654_sdhci_execute_tuning() is in fact unused as well

what do I miss?

> > > > The patch was a bit broken, but I think I managed to apply it to
> > > > v2026.01 as it was supposed to be. (master currently doesn't boot even
> > > > SPL, I don't have time right now to debug that).

[]

> > > > I attached the boot log. It does boot with your patch. Also can this be
> > > > an issue with different SD cards?
> > > 
> > > Something does not quite add up,
> > > 
> > > Can you try the following 2 commands?
> > > 
> > > # mmc dev 1
> > > # md.w 0xfa0810c
> > 
> > Finally here is the output from boot and executing these commands. I am
> > now on v2026.04-rc1 with your sweep patch.
> 
> Thanks for sending over the tap sweep. I compiled a comparison table
> here to show a bit of data for the u-boot tuning step: 
> https://gist.github.com/jmenti/5d42f1e43fb357083eaa813cfee484a8

If the above doubts have any substance, maybe those are not the results
you've expected at the end?

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com