From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (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 06C871B0F30; Mon, 25 Nov 2024 14:56:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732546598; cv=none; b=T4q1mm1+hZaPegOFIMtdlcXtz5ltN1qxsKZZRDDZkyyYojhgPvoNwgYACexQ77t+2N9c0NzLyN3wHOMGUUWZDl1J6W13F3HDn/fJq305Brbwq9N5cxD5U8T8vwVDXLKG8GCeC0XlqkO/3enjKYudNPQ68QK1LyVlScYxiUONOzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732546598; c=relaxed/simple; bh=t1dep8pStfXEPcSgbEEgowdaG41eydlmGCXSIfxnx9k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ImVOG+qw8ZTfZFK1gBE877umYem2jaWu1OJ3mwoeBasghNeJ/rTze6FmJjj8hN1ztsCyAfDFFXwLDVDyCTAi+Irn5X5APngXhnJrT8dHs7XPQhQKA6ETTx2rYp9VNj2KHRGU41oqm62S25XMS5Tpnq9Cw+g3hlayOI6EEOGW7Pw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=IRFEbkRd; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="IRFEbkRd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1732546596; x=1764082596; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=t1dep8pStfXEPcSgbEEgowdaG41eydlmGCXSIfxnx9k=; b=IRFEbkRdP9GNOw8WF+2BxkDWILBh6zXE/pGqN3I9XmYsJ51VNUmF9tX2 iSt2XHf5JwGqIearD7sEcOStGQZIOM3rnaCeQ65J+wrrq0T6rPwzFFZ1n isRaat7TWvFH5q1gw/4xMwbKianNrm69xPDruU4B2hJw89YNcpVSU7+W+ DNF5/06fByxNOqsD7dmK8JiOuLYfHSUr7VXS2BgbsMoosnbApN1sGrl7b IHsPWu2gME99oEmAy2Et09N90lfMJ18PsYQKOVrXLyi1iB2Os0BGX+kjC yRC3+Rv3iP0L390tK3NLZaxk9zrMRWcqX7JEuVFd/YnMeHbUE3OBdLt/I A==; X-CSE-ConnectionGUID: TOszqrnjQW6CecCnkbASdQ== X-CSE-MsgGUID: ot3xtuTVQ2KVjf6vylygtw== X-IronPort-AV: E=McAfee;i="6700,10204,11267"; a="44051664" X-IronPort-AV: E=Sophos;i="6.12,183,1728975600"; d="scan'208";a="44051664" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Nov 2024 06:56:35 -0800 X-CSE-ConnectionGUID: 2EOnOIAWRYWVb3RZyr6fjQ== X-CSE-MsgGUID: qjVBh5BgSxKHgVhdm0Ripg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,183,1728975600"; d="scan'208";a="91078443" Received: from bergbenj-mobl1.ger.corp.intel.com (HELO [10.245.245.34]) ([10.245.245.34]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Nov 2024 06:56:30 -0800 Message-ID: <55157183-b756-454c-89b7-aba05a293b3f@linux.intel.com> Date: Mon, 25 Nov 2024 15:56:25 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH v4 8/8] acpi_idle: Disallow play_dead with FFH cstate on AMD platforms To: Peter Zijlstra Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, rafael.j.wysocki@intel.com, len.brown@intel.com, artem.bityutskiy@linux.intel.com, dave.hansen@linux.intel.com, tglx@linutronix.de, gautham.shenoy@amd.com References: <20241125132029.7241-1-patryk.wlazlyn@linux.intel.com> <20241125132029.7241-9-patryk.wlazlyn@linux.intel.com> <20241125135454.GE38837@noisy.programming.kicks-ass.net> Content-Language: en-US From: Patryk Wlazlyn In-Reply-To: <20241125135454.GE38837@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit > So I don't like this. Less exceptions is better. > > This *SHOULD* never trigger on AMD anyway, because they recommend IO > port C[23]. But if their partner BIOS engineer does a wobbly and they > end up in MWAIT anyway, it *should* all work regardless. Agreed. I thought relaying on BIOS to not put FFH states there was a concern. I believe Gautham confirmed that AMD would be fine executing that, it's just that they prefer ioidle (or hlt?).