Subject: [PATCH] arm64: dts: rockchip: improve rk3328-roc-cc rgmii performance.

From: Peter Geis <[email-masked]>
Date: Fri, 7 Jun 2019 12:37:32 +0000

Currently the rk3328-roc-cc ethernet is enabled using "snps,force_thresh_dma_mode".
While this works, the performance leaves a lot to be desired.
A previous attempt to improve performance used "snps,txpbl = <0x4>".
This also allowed networking to function, but performance varied between boards.

This patch takes that one step further.
Set txpbl and rxpbl to 0x4.
This can also be accomplished with "snps,pbl =<0x4>" which affects both.
Also set "snps,aal" which forces address aligned DMA mode.

On my board this achieves the best performance yet, however we need broad testing to ensure this works for everyone.
Please test and provide feedback.

Signed-off-by: Peter Geis <[email-masked]>
---
 arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts b/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts
index 5d499c9086fb..8bcc08de82fb 100644
--- a/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts
@@ -141,10 +141,12 @@
 	phy-mode = "rgmii";
 	pinctrl-names = "default";
 	pinctrl-0 = <&rgmiim1_pins>;
-	snps,force_thresh_dma_mode;
 	snps,reset-gpio = <&gpio1 RK_PC2 GPIO_ACTIVE_LOW>;
 	snps,reset-active-low;
 	snps,reset-delays-us = <0 10000 50000>;
+	snps,txpbl = <0x4>;
+	snps,rxpbl = <0x4>;
+	snps,aal;
 	tx_delay = <0x24>;
 	rx_delay = <0x18>;
 	status = "okay";
-- 
2.20.1

_______________________________________________
linux-arm-kernel mailing list
[email-masked]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel