From: Jakob Unterwurzacher jakob.unterwurzacher@theobroma-systems.com
stable inclusion from stable-v5.10.107 commit f7f062919f4101505ff7ce2efccc9dcec5c334cd bugzilla: https://gitee.com/openeuler/kernel/issues/I574A2
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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@0leil.net Signed-off-by: Jakob Unterwurzacher jakob.unterwurzacher@theobroma-systems.com Signed-off-by: Quentin Schulz quentin.schulz@theobroma-systems.com Link: https://lore.kernel.org/r/20220119134948.1444965-1-quentin.schulz@theobroma-... Signed-off-by: Heiko Stuebner heiko@sntech.de Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi index 4660416c8f38..544110aaffc5 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi @@ -472,6 +472,12 @@ };
&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;