From: Jakob Unterwurzacher Date: Wed, 19 Jan 2022 13:49:48 +0000 (+0100) Subject: arm64: dts: rockchip: fix rk3399-puma eMMC HS400 signal integrity X-Git-Tag: microblaze-v5.19~314^2~4^2~4 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=62966cbdda8a92f82d966a45aa671e788b2006f7;p=linux-2.6-microblaze.git arm64: dts: rockchip: fix rk3399-puma eMMC HS400 signal integrity 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 Signed-off-by: Jakob Unterwurzacher Signed-off-by: Quentin Schulz Link: https://lore.kernel.org/r/20220119134948.1444965-1-quentin.schulz@theobroma-systems.com Signed-off-by: Heiko Stuebner --- 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;