Various RK3399 boards, including the Rock Pi 4 series, the NanoPi 4 series and possibly others showed instabilities with some eMMC modules when operating in HS400 mode [1]. Later, a missing pull-down resistor on the eMMC strobe line was identified as the root cause of these instabilities [2]. This series changes the Rockchip eMMC PHY driver to enable the internal pull-down for the strobe line by default, effectively restoring the behavior of the vendor kernel [3]. Addressing the problem in the driver avoids fix-ups in individual board DTs. As this change makes the optional DT property enable-strobe-pulldown obsolete, it is replaced by a new property disable-strobe-pulldown, that, when used, allows to disable the internal pull-down. While at it, the enable-strobe-pulldown property was removed from the NanoPi4 series DTS (which was the only user of the property in the kernel). [1]: https://lore.kernel.org/all/20230705144255.115299-1-chris.obbard@xxxxxxxxxxxxx/ [2]: https://lore.kernel.org/all/20220822074139.3810-1-jensenhuang@xxxxxxxxxxxxxxx/ [3]: https://github.com/rockchip-linux/kernel/blob/develop-4.4/drivers/phy/rockchip/phy-rockchip-emmc.c#L310 Signed-off-by: Folker Schwesinger <dev@xxxxxxxxxxxxxxxxxxxxx> --- Folker Schwesinger (3): phy: rockchip: emmc: Enable pulldown for strobe line devicetree: phy: rockchip-emmc: Document changed strobe-pulldown property arm64: dts: rockchip: Remove enable-strobe-pulldown for NanoPi4 boards Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 4 ++-- arch/arm64/boot/dts/rockchip/rk3399-nanopi4.dtsi | 1 - drivers/phy/rockchip/phy-rockchip-emmc.c | 6 +++--- 3 files changed, 5 insertions(+), 6 deletions(-) --- base-commit: 4cece764965020c22cff7665b18a012006359095 change-id: 20240326-rk-default-enable-strobe-pulldown-3356c8cf1b4f Best regards, -- Folker Schwesinger <dev@xxxxxxxxxxxxxxxxxxxxx>
