From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C2E35606A323 for ; Thu, 12 Nov 2026 10:13:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=uJE0cURK; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=YGTg2ZDf DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=ZmNNrkYoDlObKGEWXN/NM8TQ0vBE+3eTJ9t0fVYsCNk=; b=uJE0cURKYiY4AuHl7j1pxOtzI1 BgiujN43zQTjiRLdsvpMeRTZKNPtXAmVP3zbEIMDdZ+Wj4yUGYGNewVkLL/ytKerLfgPB6/FEriEg rCaSgUqPEay+iDXNiib0uH6qQh4cWIjG+Mb4aZoPbaikwjQA6W1a3LO502Kso0fjTVnSzECnhcRr3 Sl7De33aSkASBgbYts+uB7/VMxmA+PCorTGK4rNVeuEkvnx2OwAif7+ZjjAXgCU1SaUgGDoZWRZyL vQpj9TN8094j8BA52BlBdjGa2kLLgYP1hgjAcn3V/dSZ5/fjANJiSXwKq91Mp4WGwjK6x0kcfRZsr FcD9fI3Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xRRoL-00000009Tpq-33Fi; Thu, 12 Nov 2026 10:13:41 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xRRoK-00000009Tpd-0QHG for linux-arm-kernel@lists.infradead.org; Thu, 12 Nov 2026 10:13:40 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id B0E86408CC; Thu, 12 Nov 2026 10:13:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F24AA1F00A05; Thu, 12 Nov 2026 10:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794478418; bh=ZmNNrkYoDlObKGEWXN/NM8TQ0vBE+3eTJ9t0fVYsCNk=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=YGTg2ZDf3iYzt2uYHKEqZhYIdqLwemfsaiXCvrbzHPTvXrChKwnX4kZuFOLJX3VRu 2w5jyR403QHNohpvEprbr9c0+06LLW7cCLHgl5qf/wSj9AnZ1aQ60yMGyh+DopNZ1o T0oERaGZ7cobW+IZ2f5Ob1uc+2IPxbI1nvK50I94uiK2kSYd1tT2FLrQzcXQvFcJID b5lHiZLpE2BnhbCnvcnVDy9F2ysWmSOu/IZdirBBZpLG+vpPVVfpogoYfeeU8twVXZ C0AWUYxpM9IBngJum+WCKEhlNBl9WtSiNV+T4b4BJN1LxGJdKeAIQQVASqTylhcD8j rm7EFKnqbSYGw== Date: Thu, 12 Nov 2026 10:13:34 +0000 From: Sudeep Holla To: Patrick DELAUNAY Cc: Ulf Hansson , Mark Rutland , Sudeep Holla , Lorenzo Pieralisi , linux-kernel@vger.kernel.org, dario.binacchi@amarulasolutions.com, Linux STM32 , linux-arm-kernel@lists.infradead.org Subject: Re: [Linux-stm32] [PATCH] firmware: psci: handle unsupported SET_SUSPEND_MODE in PC mode Message-ID: <20261112-attentive-gregarious-beagle-9c1fbd@sudeepholla> References: <20261029191624.1.I5f8f3d75a566b72250d629ac6f43cf0d387c0218@changeid> <20261030-origami-tarantula-of-contentment-a70ab2@sudeepholla> <4690f55f-dc13-4e43-82f9-d508253f6c64@foss.st.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Thu, Nov 12, 2026 at 10:40:48AM +0100, Patrick DELAUNAY wrote: > Hi, > > To complete my previous answer, > In  last PSCI specification v1.3, we found this description: > " > 5.21 PSCI_SET_SUSPEND_MODE > 5.21.3 Caller responsibilities > The caller must be able to cope with the following error return codes: > • NOT_SUPPORTED, in which case the calling OS can assume the platform will > work in platform-coordinated mode. In this case, the PSCI_FEATURES feature > flag 0 for CPU_SUSPEND is also 0. > " > Yes, I can't disagree with that, but ...(see below) > My patch only implements this behavior: > the PSCI stack in Linux assumes PC mode when SET_SUSPEND_MODE is not > supported. > To reiterate my earlier point: if PSCI_FEATURES reports that a function is unsupported, we shouldn't invoke that FID in the first place. Dealing with an unexpected NOT_SUPPORTED return from an advertised FID is a separate case, and we must keep that handling unconditional as it currently stands. -- Regards, Sudeep