[PATCH] arm64: dts: rockchip: disable HS400 on RK3588 Tiger

[Quentin Schulz]

Hi all,

On 11/12/25 4:01 PM, Quentin Schulz wrote:
> From: Quentin Schulz <quentin.schulz at cherry.de>
> 
> We've had reports from the field that some RK3588 Tiger have random
> issues with eMMC errors.
> 
> Applying commit a28352cf2d2f ("mmc: sdhci-of-dwcmshc: Change
> DLL_STRBIN_TAPNUM_DEFAULT to 0x4") didn't help and seemed to have made
> things worse for our board.
> 
> Our HW department checked the eMMC lines and reported that they are too
> long and don't look great so signal integrity is probably not the best.
> 
> Note that not all Tigers with the same eMMC chip have errors, so the
> suspicion is that we're really on the edge in terms of signal integrity
> and only a handful devices are failing. Additionally, we have RK3588
> Jaguars with the same eMMC chip but the layout is different and we also
> haven't received reports about those so far.
> 
> Lowering the max-frequency to 150MHz from 200MHz instead of simply
> disabling HS400 was briefly tested and seem to work as well. We've
> disabled HS400 downstream and haven't received reports since so we'll go
> with that instead of lowering the max-frequency.
> 
> Signed-off-by: Quentin Schulz <quentin.schulz at cherry.de>

Went too fast and forgot:

Fixes: 6173ef24b35b ("arm64: dts: rockchip: add RK3588-Q7 (Tiger) SoM")
Cc: stable at vger.kernel.org

Will give a few days for reviews and then send a v2 next week.

Cheers,
Quentin