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 7F673CD13D3 for ; Thu, 30 Apr 2026 16:54:35 +0000 (UTC) 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-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=nT9VYwAZs4ltJMRYFKxWt+mW9C34b5if1UyYfP9fQ2k=; b=1tl9oxwrroRodyy4jDjfGYAN5R IAnyvT96M1bB0j4Uu1joViMVlzoPeSrbvcdOk3oRcb7PiRxt8EfMZtXZhys9xWKcA2p7+4+cY4nHP EMX6QpttDePPrW3z1MrqHH3VXnw6R1qjv8UdDFbY0k6l634xIWhsAgi5UmF59T5pV9JkZosvgZz5A wq1Kqh+OprufRuqoFdl/x2Sb5ZDyU0iYC5RvtHWG9HMpuQdGCqD3xCcKoJuFG/hGgtUkw/bWOeiFz bcoraF0+0FeKn9xyfdAo1K42ALk8BmH9ne0Ryd9J3kNNav8r7olVIUwE4A9gY+Eds68hpGkXz3yOv 4i4JquTg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIUej-00000005llZ-0quI; Thu, 30 Apr 2026 16:54:29 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIUeg-00000005lkx-1xNt for linux-arm-kernel@lists.infradead.org; Thu, 30 Apr 2026 16:54:27 +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 51C3F359B; Thu, 30 Apr 2026 09:54:15 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5EA6D3F62B; Thu, 30 Apr 2026 09:54:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1777568060; bh=0aE0e+1TBdahKKaq6tlLRD0Vy8TxtU1tIj610UdY+qw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kJmz3Z+nrMApGsUU4ly8Mx9Doad2qelaDVd0yRedu6aLq4CRvli4offMkfO6v6Twj 22VN4JFBi0pBI0Sn1bUMiQSQL1YTBIYL7EBJtvSUfDKGlonOZAGWH6LdAGOGx/jnq8 F3371MTuoxQiKYdnMQb0PahR5vN0FBuFp0N2cKnI= Date: Thu, 30 Apr 2026 17:54:18 +0100 From: Leo Yan To: James Clark Cc: Suzuki K Poulose , Mike Leach , Alexander Shishkin , Mathieu Poirier , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] coresight: ete: Always save state on power down Message-ID: <20260430165418.GF16537@e132581.arm.com> References: <20260428-james-cs-ete-pm_save_enable-v1-0-c7a90ca6f43b@linaro.org> <20260428-james-cs-ete-pm_save_enable-v1-1-c7a90ca6f43b@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260428-james-cs-ete-pm_save_enable-v1-1-c7a90ca6f43b@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260430_095426_552595_273460A0 X-CRM114-Status: GOOD ( 16.79 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Apr 28, 2026 at 01:18:11PM +0100, James Clark wrote: > ETE registers are always system registers so it's highly unlikely there > will be an implementation that preserves them on CPU power down. Also > the ETE DT binding never documented > "arm,coresight-loses-context-with-cpu" so nobody would have legitimately > been able to use that binding to fix it. > > Fix it by hard coding the setting for ETE and add a warning if the user > tried to use the module parameter. Don't add a warning if > loses-context-with-cpu is present in the DT as it's not a documented > binding anyway. etm4_init_pm_save() needs to happen after drvdata is > initialised so etm4x_is_ete() can be called. > > This fixes the following error when using Coresight with ACPI on the FVP > which supports CPU PM: > > coresight ete0: External agent took claim tag > WARNING: drivers/hwtracing/coresight/coresight-core.c:248 at coresight_disclaim_device_unlocked+0xe0/0xe8, CPU#0: perf/117 > > Fixes: 35e1c9163e02 ("coresight: ete: Add support for ETE tracing") > Signed-off-by: James Clark Reviewed-by: Leo Yan