Re: [PATCH] riscv: dts: spacemit: k3: enable status of mimsic and maplic to okay

From: "Troy Mitchell" <troy.mitchell@linux.spacemit.com>
To: "E Shattow" <e@freeshell.de>,
	"Anirudh Srinivasan" <asrinivasan@oss.tenstorrent.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Yixun Lan" <dlan@kernel.org>,
	"Troy Mitchell" <troy.mitchell@linux.spacemit.com>,
	"Paul Walmsley" <pjw@kernel.org>,
	"Palmer Dabbelt" <palmer@dabbelt.com>,
	"Albert Ou" <aou@eecs.berkeley.edu>,
	"Alexandre Ghiti" <alex@ghiti.fr>,
	"Guodong Xu" <docular.xu@gmail.com>
Cc: <devicetree@vger.kernel.org>, <linux-riscv@lists.infradead.org>,
	<spacemit@lists.linux.dev>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] riscv: dts: spacemit: k3: enable status of mimsic and maplic to okay
Date: Fri, 30 Oct 2026 10:03:47 +0800	[thread overview]
Message-ID: <DMHSY8103ELL.1ZNKF2EH6PDSG@linux.spacemit.com> (raw)
In-Reply-To: <20261029162343.1896134-1-e@freeshell.de>

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Hi E,

On Thu Oct 29, 2026 at 9:23 AM -0700, E Shattow wrote:
> Change the "reserved" status of mimsic and maplic to "okay". There is
> an mainline OpenSBI user of this and setting status okay resolves the
> stall of Linux when probing peripherals at boot.

Thanks for bringing this here. I still think status = "reserved" in
k3.dtsi is the right description.

(To clarify the Acked-by I gave on the U-Boot thread: it was for
carrying the override in spacemit-k3-u-boot.dtsi, not for changing
the kernel DT)

> @@ -1452,7 +1452,7 @@ mimsic: interrupt-controller@f1000000 {
>  			msi-controller;
>  			riscv,hart-index-bits = <4>;
>  			riscv,num-ids = <511>;
> -			status = "reserved";
> +			status = "okay";
>  		};
>  
>  		maplic: interrupt-controller@f1800000 {
> @@ -1464,7 +1464,7 @@ maplic: interrupt-controller@f1800000 {
>  			riscv,children = <&saplic>;
>  			riscv,delegation = <&saplic 1 512>;
>  			riscv,num-sources = <512>;
> -			status = "reserved";
> +			status = "okay";
>  		};
> Fixes: 56f37e391a62 ("riscv: dts: spacemit: add initial support for K3 SoC")
I don't think this is a bug in the kernel DT either.

This was also discussed when k3.dtsi was reviewed [1]. The DTB built
from the kernel tree is often loaded directly by the bootloader (e.g.
from /boot) instead of the FDT that OpenSBI has already fixed up. With
"okay" there, Linux would probe the M-level IMSIC/APLIC and take an
access fault. The compromise back then was to keep them out of the
kernel's view in k3.dtsi ("disabled" at first, "reserved" since v5)
and enable them for the firmware build in -u-boot.dtsi, which is
exactly what your U-Boot patch does.

(Also replacing Guodong's address with his current one in Cc.)

[1] https://lore.kernel.org/all/77f9a001-7f0a-4c29-abcb-501e875da117@sifive.com/

-- 
Troy Mitchell

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