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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0785BC433FE for ; Tue, 4 Oct 2022 05:04:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229569AbiJDFD5 (ORCPT ); Tue, 4 Oct 2022 01:03:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229479AbiJDFDy (ORCPT ); Tue, 4 Oct 2022 01:03:54 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AD3D1F62F; Mon, 3 Oct 2022 22:03:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664859833; x=1696395833; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=kviKUqiT8pBeVsCDEFp0UnRDN3zB0t0iniuXt9pOE1s=; b=E1AMY3Gh75iUL+th6zFD5rhkXVRkWBAVRabzwzAK24uJFvxnvWS5odpQ OmJyOHfeMHfxJJD/XzKs4GqXgqQdu1oHpMIBwtPbywGpgK5/2hGRyODWF 6GG5UssX/K4ZgURyP4M0t7SSbIoc00JUXEUJ3gxO1utv40YSsONPh6zPA hPSjAVm9ZAxgAmcBGbgv6g+jvO8FxeTBJr75s3T5Bq1NvLofEA35VKiS3 rFAfZalUL76Nlp2RGQvJdolzkwkPgU+1642Q8QsoXT1dUJMQGKu0GWXCj 6aF9rLg9uILhzpV+jjsBwnDSq/DS9Rxh7fH/e6P7fvQMaahkpfIpU9/lF g==; X-IronPort-AV: E=McAfee;i="6500,9779,10489"; a="302807976" X-IronPort-AV: E=Sophos;i="5.93,367,1654585200"; d="scan'208";a="302807976" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Oct 2022 22:03:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10489"; a="626054280" X-IronPort-AV: E=Sophos;i="5.93,367,1654585200"; d="scan'208";a="626054280" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga007.fm.intel.com with ESMTP; 03 Oct 2022 22:03:51 -0700 Received: by black.fi.intel.com (Postfix, from userid 1001) id F3CE8D0; Tue, 4 Oct 2022 08:04:10 +0300 (EEST) Date: Tue, 4 Oct 2022 08:04:10 +0300 From: Mika Westerberg To: Mario Limonciello Cc: "open list:THUNDERBOLT DRIVER" , linux-kernel@vger.kernel.org, Sanju.Mehta@amd.com Subject: Re: [RFC 1/3] thunderbolt: Allow XHCI device links to enter runtime pm Message-ID: References: <20221004041225.1462336-1-mario.limonciello@amd.com> <20221004041225.1462336-2-mario.limonciello@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221004041225.1462336-2-mario.limonciello@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mario, On Mon, Oct 03, 2022 at 11:12:23PM -0500, Mario Limonciello wrote: > Both on Intel's and AMD's USB4 designs it's important that the device > link to the XHCI controller used for tunneling is able to go into D3 > for appropriate low power consumption features as well as for system > suspend states such as s0i3. > > Historically this is accomplished by adding to a hardcoded list in the > XHCI driver, but this requires a change for every single platform. > > We have a very good proxy that it's safe to do this since the firmware > has indicated the device link needs to be made. So opt all XHCI > controllers with these device links into runtime PM. This is good idea. However, it misses the fact that we have FW CM as well in Intel integrated TBT platforms (ICL, TGL and ADL) and with those you don't have the device link (I think ADL has it for both, though) so we would still need to keep the list in xHCI.