[PATCH v3 0/2] arm64: dts: mt7981/openwrt-one: UART labels and console

[PATCH v3 0/2] arm64: dts: mt7981/openwrt-one: UART labels and console

[Bryan Hinton]

This series makes two small updates for MT7981:

- Patch 1/2: Add stable labels (uart0, uart1, uart2) in the SoC dtsi so
  that board dts files can reference them directly.
- Patch 2/2: Update the OpenWrt One board dts to define serial0 alias,
  set chosen stdout-path, and enable uart0.

Both patches were build-tested (dtbs) and boot-tested: mainline Image+DTB
built and loaded via U-Boot on MT7981 hardware, with serial console output
verified.

Changes in v3:
- Patch 1/2: Unchanged.
- Patch 2/2: Drop disallowed 'current-speed' from uart0 per dtbs_check.
  Console baud is already specified via stdout-path.

Thanks,
Bryan

---

Bryan Hinton (2):
  arm64: dts: mediatek: mt7981b: add labels for UART0/1/2 nodes
  arm64: dts: mediatek: mt7981b: OpenWrt One: set console UART to 115200

 arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts | 12 ++++++++++++
 arch/arm64/boot/dts/mediatek/mt7981b.dtsi            |  6 +++---
 2 files changed, 15 insertions(+), 3 deletions(-)

-- 
2.51.0

[PATCH v3 1/2] arm64: dts: mediatek: mt7981b: add labels for UART0/1/2 nodes

[Bryan Hinton]

Add stable labels (uart0, uart1, uart2) to the MT7981B SoC UART nodes so
board DTS files can reference them directly. This change is purely
cosmetic and introduces no functional differences.

Verification: Built dtbs and boot-tested mainline Image+DTB via U-Boot on
MT7981B hardware; decompiled DT shows the uart0 label present and the
serial0 alias (or absolute path) resolves to serial@11002000.

Signed-off-by: Bryan Hinton <bryan@bryanhinton.com>
---
 arch/arm64/boot/dts/mediatek/mt7981b.dtsi | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt7981b.dtsi b/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
index 5cbea9cd411f..4ee7fb83000d 100644
--- a/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
@@ -94,7 +94,7 @@ pwm@10048000 {
 			#pwm-cells = <2>;
 		};
 
-		serial@11002000 {
+		uart0: serial@11002000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11002000 0 0x100>;
 			interrupts = <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>;
@@ -105,7 +105,7 @@ serial@11002000 {
 			status = "disabled";
 		};
 
-		serial@11003000 {
+		uart1: serial@11003000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11003000 0 0x100>;
 			interrupts = <GIC_SPI 124 IRQ_TYPE_LEVEL_HIGH>;
@@ -116,7 +116,7 @@ serial@11003000 {
 			status = "disabled";
 		};
 
-		serial@11004000 {
+		uart2: serial@11004000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11004000 0 0x100>;
 			interrupts = <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
-- 
2.51.0

[PATCH v3 2/2] arm64: dts: mediatek: mt7981b: OpenWrt One: set console UART to 115200

[Bryan Hinton]

Use the new uart0 label for the console and make the speed explicit by
setting stdout-path = "serial0:115200n8" under /chosen. This keeps the
DTS OS-agnostic: no bootargs or distribution-specific properties are
added.

Drop the 'current-speed' property from uart0 as it is not allowed by the
mediatek UART binding. The baud is already provided via stdout-path.

Verification: Boot-tested with mainline Image+DTB via U-Boot on OpenWrt
One (MT7981B). Serial console active at 115200, DTB decompile
confirms serial0 alias and stdout-path set correctly.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202509211032.0rJjPoYE-lkp@intel.com/
Signed-off-by: Bryan Hinton <bryan@bryanhinton.com>
---
 arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts b/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
index 4f6cbb491287..968b91f55bb2 100644
--- a/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
@@ -8,8 +8,20 @@ / {
 	compatible = "openwrt,one", "mediatek,mt7981b";
 	model = "OpenWrt One";
 
+	aliases {
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
 	memory@40000000 {
 		reg = <0 0x40000000 0 0x40000000>;
 		device_type = "memory";
 	};
 };
+
+&uart0 {
+	status = "okay";
+};
-- 
2.51.0

Re: [PATCH v3 0/2] arm64: dts: mt7981/openwrt-one: UART labels and console

[AngeloGioacchino Del Regno]

Il 22/09/25 05:58, Bryan Hinton ha scritto:
> This series makes two small updates for MT7981:
> 
> - Patch 1/2: Add stable labels (uart0, uart1, uart2) in the SoC dtsi so
>    that board dts files can reference them directly.
> - Patch 2/2: Update the OpenWrt One board dts to define serial0 alias,
>    set chosen stdout-path, and enable uart0.
> 
> Both patches were build-tested (dtbs) and boot-tested: mainline Image+DTB
> built and loaded via U-Boot on MT7981 hardware, with serial console output
> verified.
> 

Whole series is

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Thanks!

Re: [PATCH v3 0/2] arm64: dts: mt7981/openwrt-one: UART labels and console

[AngeloGioacchino Del Regno]

On Sun, 21 Sep 2025 22:58:08 -0500, Bryan Hinton wrote:
> This series makes two small updates for MT7981:
> 
> - Patch 1/2: Add stable labels (uart0, uart1, uart2) in the SoC dtsi so
>   that board dts files can reference them directly.
> - Patch 2/2: Update the OpenWrt One board dts to define serial0 alias,
>   set chosen stdout-path, and enable uart0.
> 
> [...]

Applied to v6.18-next/dts64, thanks!

[1/2] arm64: dts: mediatek: mt7981b: add labels for UART0/1/2 nodes
      commit: c0a824edb6bf694a2d5a9eede29e1628f093cb22
[2/2] arm64: dts: mediatek: mt7981b: OpenWrt One: set console UART to 115200
      commit: 36712c5cf980980139bd8f7b84b1b6daec068857

Cheers,
Angelo