From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C1BDACA5537 for ; Wed, 13 Sep 2023 10:53:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To: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-Owner; bh=KtFlBPE+Xxv5l0rqjaC7JlAbU5ldfPDpnLIpz91mZAg=; b=kA+VIhXYwVe7ev nl7H3NYOoKjrdOmoBatyB7cv3gMc+1NJywgaHA/+vG/exeSWwrs6d+u+5h+jGkwwSO6k5a0DGSisu gGv0AllqcaOl27I1c1gO+ZU8Oa66gKlFEkF4PJAXM5kH0jFs0eJVUoAx0mpZeF/nSbMSENdR5NUQB gFvmHsDpIK4DLdxbbHhtHrpnjbdQKHsXIlRgcTD52Gy+NxIoPO/kIyKms+9L9WfQsXjS55LChCa2O JYJfRxlLgNOfc9Gs9JyQwQ8Z5qiDXt3kC9FyULWvNBxJbCaeiwRqx1yAHjqtg03srkIL6XpX2Zqrq yXUQ/a+VgjioEI6fS7fA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgNUN-005fPN-04; Wed, 13 Sep 2023 10:52:55 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgNUJ-005fNi-2f for linux-arm-kernel@lists.infradead.org; Wed, 13 Sep 2023 10:52:53 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D25C51FB; Wed, 13 Sep 2023 03:53:26 -0700 (PDT) Received: from bogus (unknown [10.57.93.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A941C3F5A1; Wed, 13 Sep 2023 03:52:47 -0700 (PDT) Date: Wed, 13 Sep 2023 11:51:48 +0100 From: Sudeep Holla To: Will Deacon Cc: Oza Pawandeep , catalin.marinas@arm.com, Sudeep Holla , rafael@kernel.org, lenb@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [PATCH v5] cpuidle, ACPI: Evaluate LPI arch_flags for broadcast timer Message-ID: <20230913105148.xntz3qeascibvuxx@bogus> References: <20230912172933.3561144-1-quic_poza@quicinc.com> <20230913083908.dfanwizomj5i536k@bogus> <20230913102721.GB12021@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230913102721.GB12021@willie-the-truck> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230913_035251_908940_E5BE7136 X-CRM114-Status: GOOD ( 25.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Sep 13, 2023 at 11:27:21AM +0100, Will Deacon wrote: > On Wed, Sep 13, 2023 at 09:43:01AM +0100, Sudeep Holla wrote: > > On Tue, Sep 12, 2023 at 10:29:33AM -0700, Oza Pawandeep wrote: > > > Arm=EF=BF=BD Functional Fixed Hardware Specification defines LPI stat= es, > > > which provide an architectural context loss flags field that can > > > be used to describe the context that might be lost when an LPI > > > state is entered. > > > = > > > - Core context Lost > > > - General purpose registers. > > > - Floating point and SIMD registers. > > > - System registers, include the System register based > > > - generic timer for the core. > > > - Debug register in the core power domain. > > > - PMU registers in the core power domain. > > > - Trace register in the core power domain. > > > - Trace context loss > > > - GICR > > > - GICD > > > = > > > Qualcomm's custom CPUs preserves the architectural state, > > > including keeping the power domain for local timers active. > > > when core is power gated, the local timers are sufficient to > > > wake the core up without needing broadcast timer. > > > = > > > The patch fixes the evaluation of cpuidle arch_flags, and moves only = to > > > broadcast timer if core context lost is defined in ACPI LPI. > > > = > > > Reviewed-by: Sudeep Holla > > = > > IIRC, Rafael had acked this, perhaps missing the tag ? > > Also just add a note to Will/Catalin that Rafael has acked and prefer to > > take it via arm64 tree. > = > Is this a fix? If so, please can I have a "Fixes:" tag (and does it need = to > go into stable?) > Well, most platform today have CPUIDLE_CORE_CTXT set so the existing code works as expected. It is this Qcom platform that doesn't set it and need different behaviour. So based on their requirement for running stable tree, the fixes tag can be added. In short yes it can be seen as a fix if this new requirement is considered. Sorry the main reason for trying to avoid is there are multiple patches adding the initial support and there has been some code restructuring around this. So it may need proper backporting based on the version. I just want to avoid if there is no real requirement for that. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel