This is a note to let you know that I've just added the patch titled arm64: dts: rockchip: fix rk3399-puma eMMC HS400 signal integrity to the 5.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-dts-rockchip-fix-rk3399-puma-emmc-hs400-signal.patch and it can be found in the queue-5.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8da9c7e83c2775f63197f560a1922b8c8f460bb2 Author: Jakob Unterwurzacher <jakob.unterwurzacher@xxxxxxxxxxxxxxxxxxxxx> Date: Wed Jan 19 14:49:48 2022 +0100 arm64: dts: rockchip: fix rk3399-puma eMMC HS400 signal integrity [ Upstream commit 62966cbdda8a92f82d966a45aa671e788b2006f7 ] There are signal integrity issues running the eMMC at 200MHz on Puma RK3399-Q7. Similar to the work-around found for RK3399 Gru boards, lowering the frequency to 100MHz made the eMMC much more stable, so let's lower the frequency to 100MHz. It might be possible to run at 150MHz as on RK3399 Gru boards but only 100MHz was extensively tested. Cc: Quentin Schulz <foss+kernel@xxxxxxxxx> Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220119134948.1444965-1-quentin.schulz@xxxxxxxxxxxxxxxxxxxxx Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi index 002ece51c3ba..08fa00364b42 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi @@ -439,6 +439,12 @@ }; &sdhci { + /* + * Signal integrity isn't great at 200MHz but 100MHz has proven stable + * enough. + */ + max-frequency = <100000000>; + bus-width = <8>; mmc-hs400-1_8v; mmc-hs400-enhanced-strobe;