Re: [PATCH v4 5/5] arm64: dts: renesas: R8A78000: Add initial Ironhide support
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2025-09-17 15:04:57
Also in:
linux-devicetree, linux-perf-users, linux-renesas-soc
Hi Morimoto-san, On Wed, 17 Sept 2025 at 07:31, Kuninori Morimoto [off-list ref] wrote:
From: Hai Pham <redacted> Add the initial support for Renesas X5H Ironhide board. Note: It is using "maxcpus" in bootargs to limit number of CPU, because SMP support is now under development. This limitation will be removed in the future. [Kuninori: tidyup for upstreaming] Signed-off-by: Hai Pham <redacted> Signed-off-by: Vinh Nguyen <redacted> Signed-off-by: Takeshi Kihara <redacted> Signed-off-by: Khanh Le <redacted> Signed-off-by: Huy Bui <redacted> Signed-off-by: Phong Hoang <redacted> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Thanks for the update!
quoted hunk ↗ jump to hunk
--- /dev/null +++ b/arch/arm64/boot/dts/renesas/r8a78000-ironhide.dts@@ -0,0 +1,92 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* + * Device Tree Source for the Ironhide board + * + * Copyright (C) 2025 Renesas Electronics Corp. + */ + +/dts-v1/; +#include "r8a78000.dtsi" + +/ { + model = "Renesas Ironhide board based on r8a78000"; + compatible = "renesas,ironhide", "renesas,r8a78000"; + + aliases { + serial0 = &hscif0; + }; + + chosen { + /* + * REMOVE-ME + * + * It works 1 CPU core only for now. This limitation will be + * removed in future. + */ + bootargs = "maxcpus=1";
I still don't fully understand why this is needed: without that line, Ironhide boots fine, and only a single CPU is enabled. None of the cpu node have an enable-method, so Linux does not try to enable secondary CPUs anyway. Even with the enable-method re-added (like in your v2), Linux cannot enable secondary CPUs, as there is no PSCI node. What am I missing?
+ stdout-path = "serial0:1843200n8"; + };
The rest LGTM.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds