Re: [PATCH v2 4/4] riscv: dts: spacemit: Add Milk-V Jupiter board (M1)

From: Yixun Lan <dlan@kernel.org>
To: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-kernel@vger.kernel.org, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	"open list:RISC-V ARCHITECTURE" <linux-riscv@lists.infradead.org>,
	"open list:RISC-V SPACEMIT SoC Support"
	<spacemit@lists.linux.dev>
Subject: Re: [PATCH v2 4/4] riscv: dts: spacemit: Add Milk-V Jupiter board (M1)
Date: Thu, 30 Jul 2026 08:54:24 +0000	[thread overview]
Message-ID: <20260730085424-GKK76518@kernel.org> (raw)
In-Reply-To: <20260729160749.1621415-5-aurelien@aurel32.net>

Hi Aurelien, 

On 18:00 Wed 29 Jul     , Aurelien Jarno wrote:
> Add support for the Milk-V Jupiter board with the M1 CPU. The M1 differs
> from the K1 only by its package, which provides improved cooling
> performance and allows it to run at up to 1.8 GHz instead of 1.6 GHz.
> 
> Add m1-opp.dtsi to define the 1.8 GHz operating point and the
> corresponding core voltage, based on the upstream kernel. Include it
> from m1-milkv-jupiter.dts. Raise the maximum buck1 voltage to 1.116V to
> match the new operating point.
> 
While checking the schematics, the buck1,2 provide power supply both
for cpu core and AVDD09 domain - check schematics page 9/25 [1]

the R81 is NC, so buck1,2 is actually all power supply, raise voltage will
result high risk to damage the chip (overvoltage of AVDD09 domain), so
a safe strategy would to test if M1 able to run at 1.8G without voltage 
change (still at 1.05v)?

Link: https://github.com/milkv-jupiter/jupiter-files/blob/main/hardware/v1_0/jupiter-sch-v1_0.pdf [1]

-- 
Yixun Lan (dlan)