From 8d3206ee456a5ecdf9ddbfd8e5e231e4f0cd716e Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 6 May 2025 13:37:00 +0100 Subject: [PATCH] arm64: dts: bcm2712-rpi: Add uart0_dma parameter It seems that some applications don't work with UART DMA enabled, while others don't work without it. No DMA seems to be the safer default choice, but add a dtparam - uart0_dma - to re-enable it. See: https://github.com/raspberrypi/linux/issues/6365 Signed-off-by: Phil Elwell --- arch/arm/boot/dts/overlays/README | 3 +++ arch/arm64/boot/dts/broadcom/bcm2712-rpi.dtsi | 5 +++++ 2 files changed, 8 insertions(+) --- a/arch/arm/boot/dts/overlays/README +++ b/arch/arm/boot/dts/overlays/README @@ -460,6 +460,9 @@ Params: 6, 8 and 10 of the 40-way header (2712 only, default "off") + uart0_dma Enable DMA usage on UART0 (2712 only, default + "off") + uart1 Set to "on" or "off" to enable or disable uart1 (default varies) --- a/arch/arm64/boot/dts/broadcom/bcm2712-rpi.dtsi +++ b/arch/arm64/boot/dts/broadcom/bcm2712-rpi.dtsi @@ -220,6 +220,11 @@ pio: &rp1_pio { suspend = <&pwr_key>, "linux,code:0=205"; uart0 = <&uart0>, "status"; uart0_console = <&uart0>,"status", <&aliases>, "console=",&uart0; + uart0_dma = <&uart0>,"dmas:0=",<&rp1_dma>, + <&uart0>,"dmas:4=",, + <&uart0>,"dmas:8=",<&rp1_dma>, + <&uart0>,"dmas:12=",, + <&uart0>,"dma-names[=747800727800"; // "tx", "rx" wifiaddr = <&wifi>, "local-mac-address["; cam0_reg = <&cam0_reg>,"status";