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authorChristoph Muellner <christoph.muellner@theobroma-systems.com>2019-02-28 16:06:40 +0100
committerChristoph Muellner <christoph.muellner@theobroma-systems.com>2019-05-21 18:23:43 +0200
commit7e93719067dce93363529a7cc13f478c6b6d9158 (patch)
tree4d55613b6718b47218ea9b14723026a6a9865952
parent1560f21c4ffe10824f3a7eab69e6a557f69ec83f (diff)
arm64: dts: rockchip: Decrease emmc-phy's drive impedance on rk3399-pumaHEADpuma-release-4.4.126-2018-04-12
The RK3399-Q7 (Puma) requires 33 Ohm drive strength to ensure signal integrity at HS-400 (200MHz clock, DDR signalling). A repeated EMC testing run validates that this increase does not negatively impact EMC compliance (emissions have ample distance to the regulatory limits). Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com> Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> Tested-by: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com> Tested-by: Klaus Goger <klaus.goger@theobroma-systems.com>
-rw-r--r--arch/arm64/boot/dts/rockchip/rk3399-puma.dts1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma.dts b/arch/arm64/boot/dts/rockchip/rk3399-puma.dts
index b8e316eed69d..481a30d182ee 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-puma.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-puma.dts
@@ -366,6 +366,7 @@
&emmc_phy {
status = "okay";
+ drive-impedance-ohm = <33>;
};
&gmac {