On Sat, 08 May 2021 22:56:57 +0200, Lucas Stach wrote:

HS400 requires a data strobe line in addition to the other MMC signal
lines, so if a board design neglects to wire up this signal, HS400 mode
is no available, even if both the controller and the eMMC are claiming
to support this mode. Add a DT flag to allow boards to disable the
HS400 support in this case.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
---
 Documentation/devicetree/bindings/mmc/mmc-controller.yaml | 5 +++++
 1 file changed, 5 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>