From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D6F9B348C7B; Sat, 19 Sep 2026 23:13:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789859617; cv=none; b=k1u4LfNHM8uz9SUU6nY12iqab1o5qS53yEWfkiVXdimnDVND5lHsntLS6F1S9dOD+o+wIjq6OJqWuRM1OJGLA5YAuzOrV5auypH66fimR9HZwnOHZHx6h+BFdI0nTXxtlOUlMB/BaTTBM8ZyvGstN0hFSGOmzfT597wQH0rjrAs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789859617; c=relaxed/simple; bh=sK2yacM6Q3NGD6pgtUu/ouaNBLyacVN5mFpthK3M0EE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Eo+2g1bZBJEDqv0mCtw2MokV1q1X6LQnhTiYiw0KOI1sJU8Fd6zmkDRAzj6RsIlv/n96zRKg2ITYKc2ZhjoK/V+0T/rIU2G906xXIB98mlQLzKs3/2yffeDDTT4oTEaw0kMS5jJ8j/4/1988y0ITvxStn5sAC0fL+Doies0m834= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=agsW2GL4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="agsW2GL4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E960B1F000FF; Sat, 19 Sep 2026 23:13:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789859615; bh=2Sef/0wxyMwTpjYCRnlB9CgtNUDrbK2hMY8qeX5WdGA=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=agsW2GL4vTTRqpy7+o1jwke4n1/xbLd5GX9CLNxEpk/J+J6CA5r6gJkG1jKju+NPm wMOwUqTa8PrIQ5wkmYvByON9AH34njGzQIckoWUQPP6lfYsVH1JubRrXOdrW/fDw1f J2KFvOBBVO/gh08nduHOQAzcOQ9ftbLQRO7OVHCnjhE6vE1wWWV93XFIHgu/NnTaQy bwWdMoTMk2f5hcq3K2BvqZN+6n8vMasxFKOUFPoOB/yX3n73ayxbMRHE+cQ9UhK+Rg 2as9+UFbBD1l4QEoqvsNfhlrtSmWN6j5jQbj2zLUJ0MnCtSxGzVIQUE/LcE7liMVkP JWzwOrSYgSyVg== Date: Sat, 19 Sep 2026 23:13:33 +0000 From: Yixun Lan To: Icenowy Zheng Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Ulf Hansson , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , devicetree@vger.kernel.org, linux-riscv@lists.infradead.org, spacemit@lists.linux.dev, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH 2/3] pmdomain: spacemit: Add power domain driver Message-ID: <20260919231333-GKB322102@kernel.org> References: <20260918-04-k3-pm-support-v1-0-0acd2b36b96f@kernel.org> <20260918-04-k3-pm-support-v1-2-0acd2b36b96f@kernel.org> <20260918230107-GKC297024@kernel.org> <33b33b2b79763d410bc2e5b4ef46c305aaf6f7c8.camel@icenowy.me> <20260919095936-GKA322102@kernel.org> <8301abce221e33d827053c54a64aed05f3227f7f.camel@icenowy.me> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <8301abce221e33d827053c54a64aed05f3227f7f.camel@icenowy.me> Hi Icenowy, On 21:56 Sat 19 Sep , Icenowy Zheng wrote: > 在 2026-09-19六的 09:59 +0000，Yixun Lan写道： > > Hi Icenowy, > > > > On 14:57 Sat 19 Sep     , Icenowy Zheng wrote: > > > 在 2026-09-18五的 23:01 +0000，Yixun Lan写道： > > > > Hi Icenowy, > > > > > > > > On 17:00 Fri 18 Sep     , Icenowy Zheng wrote: > > > > > 在 2026-09-18五的 02:40 +0000，Yixun Lan写道： > > > > > >   SpacemiT's PMU (Power Management Unit) consist of several > > > > > > power > > > > > > domains > > > > > > which can be managed independently, depending on different > > > > > > application > > > > > > scenario, each domain can be powered on/off for saving power. > > > > > > > > > > > >   The driver is implemented based on Linux Generic PM Domain > > > > > > framework. > > > > > > From a hardware perspective, either of two distinct power-on > > > > > > sequences > > > > > > are supported, in software mode (SW mode), the driver is > > > > > > responsible > > > > > > for > > > > > > controlling the states of bits such as sleep1, sleep2, > > > > > > isolation > > > > > > and > > > > > > pwr_state, while in hardware mode (HW mode), the PMU hardware > > > > > > will > > > > > > complete > > > > > > the sequence automatically without requiring software > > > > > > intervention. > > > > > > > > > > I think there also exists solutions for K3 that uses RPMI power > > > > > domains, and let their ESOS firmware to access the hardware. > > > > > > > > > Yes, I'm aware of that > > > > > > > > > What's the relationship of this implementation with the ESOS > > > > > implementation? Should the ESOS part be disabled to use this > > > > > implementation? > > > > > > > > > I should say, it's a mutually exclusive solution, so yes, the > > > > ESOS > > > > part > > > > should be disabled in order to use this version > > > > > > > > The motivation of this patch is trying to support drm/display > > > > driver's > > > > PM requirement, while avoid going with vendor's complicated RPMI > > > > solution > > > > which isn't mainline ready > > > > > > Is this a long-term solution, or a temporary one? > > > > > For upstream, I'd say we probably will stick to this solution for > > long time, won't say it 'forever', see comment below.. > > > > > If it's a temporary conflicting one, I don't think it's worth > > > picking > > > at all. > > > > > Well, checked current Linux kernel status, there is no RPMI PM > > solution > > implemented although there is documentation in riscv-rpmi spec[1] > > I have seen pending patch for it with multiple revisions [1], the dt > binding is even already ACKed by Conor, so I think it's not a big > problem here. > That's exactly what I said - it's not mature, not saying it's pending patch for review, but for whole solution that involve Linux driver, opensbi and underlying fimware (ESOS) - which not upstream-ed.. To make it clear, I'm not going to pursue the RPMI solution, but if someone insist and willing to spend the effort, please feel free to push -- Yixun Lan (dlan)