From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794238128; b=oKYu73/PbfwlnvkMu4k2kyFpaYwuHYklp9fyMoaCXkk5NEUo/xDnScejR56u9M5/tcva 9AifvoLyzT3wNrKsKy0AjX7Cgm8UQbj+5OIw7rtOxVUuwnx3LTY0H0V64H1MbdEuf1a8/ +yJhidp2AkoQ7/VHQl8V5cuIWv+5qbcU/V4ixfAPCHlzXwDEW3LvOqxn9Jf9kVxo0r2SA giiKCgrQp1e0Rouh5QcoSW/lGRryWTWob0yZY9ShE05rpn337UgNJMNNdZxKo9ZCCDFex gaGSB9N8YwSbh+gQF6b+GLGXcV45sxigQSvDDSRGkRAFQTBaFdhM6NmpXgoUwH4eQBw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794238128; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition: Content-Transfer-Encoding:In-Reply-To; bh=mCRGrIzDRdJ3fj5LcFpJR8WKCIeELn3A3rZQ9kvKhd0=; b=EnkfCT3u6r5FJ+uWddEsKcloVHUl1Y2M4HZPpzPCqSHKXoNEn9DrCpeV1Cidzx9PQY/O sL8gKws1bVHt+uAkx0rskItxsbt9eNIajlK0K+arTuMTkOplKGcRBwGb6prPC3DmjZ0Za rk6JtNRPZz4ysgfifk3r0HTkyanZmqEVaO5frTEMxobJFvHTSLNfvooUL6928ln75mRBs WTNLkQz31APRafZlw1u7u3HdB5uGobez22bqdvicGiDLmkzB1sckVNv+4XcEkYrcDmPOI TT4hy/dcCDY9p3g/WoQ7FVFSGzGfKwCWBQnJc53Bw+jR08AlVCDK+qwwYdZX28tYlXg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mt+BvO99; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2E7A9606A321; Mon, 9 Nov 2026 15:28:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mt+BvO99 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 412481F0089F; Mon, 9 Nov 2026 15:28:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794238127; bh=mCRGrIzDRdJ3fj5LcFpJR8WKCIeELn3A3rZQ9kvKhd0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=mt+BvO99SAb4PB7qhXL0QzsqKiFAgnV29mtcED/SiQZtMrENK8xK+1dS8lTaZvifa o4UOQ+ZgJw9dpcRbDjABLR0oiNJ4wz/Q3n0r16ne0irTox6ilYYFZ257xe5/tqFdht u4mmr/NkRvEDymrd8c0F1y/EtoMatF5tNhvKkwGhZdCK/5UmesFdUX5D46e8f9oxJs 3np7sBELOph7fdAwU43PDmuKJWjzf7kU0qxnclfBUAmXLVP0MLuFLTL2kNQXxbtZX8 CCCEbL+9kgtzYVpKUL/99P0VF1p2dN6oxSA5uICLriH/+W9GaDxH3eqv40hqdFtmc6 Jv4dnSTzbsFtQ== Date: Mon, 9 Nov 2026 15:28:43 +0000 From: Sudeep Holla To: Ulf Hansson Cc: Maulik Shah , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Ulf Hansson , "Rafael J. Wysocki" , Bjorn Andersson , Konrad Dybcio , Abel Vesa , Daniel Lezcano , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH 2/3] pmdomain: Add support for system-suspend-only states Message-ID: <20261109-swinging-inventive-wrasse-e82ec8@sudeepholla> References: <20261006-romantic-stalwart-seriema-90e71d@sudeepholla> <20261009-frisky-rottweiler-from-avalon-6c409e@sudeepholla> <20261009-skilled-mature-bittern-2206fc@sudeepholla> <20261014-prudent-mini-duck-377cb6@sudeepholla> <20261028-imported-pistachio-unicorn-2ecfec@sudeepholla> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, Nov 09, 2026 at 04:05:56PM +0100, Ulf Hansson wrote: > On Wed, Oct 28, 2026 at 12:48 PM Sudeep Holla wrote: > > [...] > > Now I understood the requirement much better. The core issue with OSI is > > that it fails unless the platform downgrades special system states to > > non-system states during routine CPUIdle paths. > > > > This leaves us with two directions for OSI: > > 1. Firmware Resolution: Handle state transitions entirely in firmware. > > 2. OS Intervention: Enforce the handling via the OS. > > > > Though I personally prefer (1), I don't have strong arguments against (2) > > now that you made me understand the requirement. Sorry for taking time, > > but mentally I was assuming (1) even for OSI until your above response. > > > > Since PC mode relies on the firmware to manage these states natively, this > > binding isn't required for it. Therefore, Could we restrict this specific > > binding exclusively to OSI implementations ? > > I guess we could, but that seems rather messy. According to earlier > discussions, if I recall correctly, we deliberately avoided OSI > specific DT bindings/properties, since support for OSI mode should be > detected through the FW. > Fair enough, we should at the least warn if used on the systems in PC CPU suspend mode. > Also note that the domain-idle-state DT bindings > (Documentation/devicetree/bindings/power/domain-idle-state.yaml) are > generic and used by RISC-V SBI as well. > Agreed. -- Regards, Sudeep