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* [PATCH/RFC] arm64: dts: renesas: ebisu, draak: Limit EtherAVB to 100Mbps
@ 2019-04-08  8:31 ` Simon Horman
  0 siblings, 0 replies; 12+ messages in thread
From: Simon Horman @ 2019-04-08  8:31 UTC (permalink / raw)
  To: linux-renesas-soc
  Cc: linux-arm-kernel, Magnus Damm, Yoshihiro Shimoda, Wolfram Sang,
	Sergei Shtylyov, Simon Horman

* According to the R-Car Gen3 Hardware Manual Errata for Rev 1.00 of
  August 24, 2018, the TX clock internal delay mode isn't supported
  on R-Car E3 (r8a77990) and D3 (r8a77995).

* TX clock internal delay mode is required for reliable 1Gbps communication
  using the KSZ9031RNX phy present on the Ebisu and Draak boards.

Thus, the E3 based Ebisu and D3 based Draak boards reliably use 1Gbps and
the speed should be limited to 100Mbps.

Based on work by Kazuya Mizuguchi.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
 arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts | 1 +
 arch/arm64/boot/dts/renesas/r8a77995-draak.dts | 1 +
 2 files changed, 2 insertions(+)

 Based on renesas-devel-20190404-v5.1-rc3

diff --git a/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts b/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts
index c72772589953..05214b8dd2c5 100644
--- a/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts
+++ b/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts
@@ -272,6 +272,7 @@
 		interrupt-parent = <&gpio2>;
 		interrupts = <21 IRQ_TYPE_LEVEL_LOW>;
 		reset-gpios = <&gpio1 20 GPIO_ACTIVE_LOW>;
+		max-speed = <100>;
 	};
 };
 
diff --git a/arch/arm64/boot/dts/renesas/r8a77995-draak.dts b/arch/arm64/boot/dts/renesas/r8a77995-draak.dts
index a7dc11e36fd9..80d82bd047fd 100644
--- a/arch/arm64/boot/dts/renesas/r8a77995-draak.dts
+++ b/arch/arm64/boot/dts/renesas/r8a77995-draak.dts
@@ -175,6 +175,7 @@
 		reg = <0>;
 		interrupt-parent = <&gpio5>;
 		interrupts = <19 IRQ_TYPE_LEVEL_LOW>;
+		max-speed = <100>;
 	};
 };
 
-- 
2.11.0


^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2019-04-10  9:27 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-04-08  8:31 [PATCH/RFC] arm64: dts: renesas: ebisu, draak: Limit EtherAVB to 100Mbps Simon Horman
2019-04-08  8:31 ` Simon Horman
2019-04-08  8:41 ` Wolfram Sang
2019-04-08  8:41   ` Wolfram Sang
2019-04-08  9:45   ` Simon Horman
2019-04-08  9:45     ` Simon Horman
2019-04-08 10:56     ` Wolfram Sang
2019-04-08 10:56       ` Wolfram Sang
2019-04-08 21:26 ` Andrew Lunn
2019-04-08 21:26   ` Andrew Lunn
2019-04-10  9:27   ` Simon Horman
2019-04-10  9:27     ` Simon Horman

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