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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 41F31C369D9 for ; Thu, 1 May 2025 02:19:26 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AB21D10E08D; Thu, 1 May 2025 02:19:25 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="nXsQ2hfJ"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id D431010E08D for ; Thu, 1 May 2025 02:19:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1746065964; x=1777601964; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=Thy9ns+rz+k09Xe98tA/ig1CGq+s0aZWZ1Vc3qMm2aU=; b=nXsQ2hfJnMc9LzyUeQ3B6a/bXFPhhS8MsnroUis5k9ul6U9wPK4vdYZt l0qqcDTZ0vRr4hyQRC+lD2EKsGGgNtYC5A+pVUrylNRm1E5CDCjpwEtUK cRTyfJe/Sn/rpjBEE3bs6l3UXJgS5PV6pKKsdSSZGKmDV8kE2P0SaYoV7 tKyBLfoM0cic2lRAOh5TRvLgfnRfxLVzXzfIjgwxpgfiRAFzKudpFjVM1 v6bS1zNN21P3o8w6UX/cbWuD3FE8fJ3ji+kLw4EPZ2Jws3i0c2J6jU+JK bvqZmxdezGeqjwLA+jvTg+2HAxTl75T5pp7y9csGtL1EIwJnpnxsgXjbi g==; X-CSE-ConnectionGUID: oW1AjokORgOFlwMocCb4DQ== X-CSE-MsgGUID: 8mI3hbNHRluoyg7N3LmkvQ== X-IronPort-AV: E=McAfee;i="6700,10204,11419"; a="47886365" X-IronPort-AV: E=Sophos;i="6.15,253,1739865600"; d="scan'208";a="47886365" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Apr 2025 19:19:22 -0700 X-CSE-ConnectionGUID: E7nhvkukQ86wDvTfuSkTrw== X-CSE-MsgGUID: PQmjmZZFQGiIqc2zGMkQww== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,253,1739865600"; d="scan'208";a="171516309" Received: from black.fi.intel.com ([10.237.72.28]) by orviesa001.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Apr 2025 19:19:20 -0700 Date: Thu, 1 May 2025 05:19:16 +0300 From: Raag Jadav To: "Vivi, Rodrigo" Cc: "intel-xe@lists.freedesktop.org" , "Nilawar, Badal" , "Tauro, Riana" , "Gupta, Anshuman" , "De Marchi, Lucas" Subject: Re: [PATCH v4 0/3] BMG PCIe Gen5 downgrade attributes and usage Message-ID: References: <20250425140626.3082588-1-raag.jadav@intel.com> <8b0ca59b5c5ed0cf5fb3efb844afa84fe3c39570.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <8b0ca59b5c5ed0cf5fb3efb844afa84fe3c39570.camel@intel.com> X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Thu, May 01, 2025 at 01:10:49AM +0530, Vivi, Rodrigo wrote: > On Tue, 2025-04-29 at 08:38 +0300, Raag Jadav wrote: > > On Mon, Apr 28, 2025 at 04:09:05PM -0400, Rodrigo Vivi wrote: > > > On Mon, Apr 28, 2025 at 04:00:44PM -0400, Rodrigo Vivi wrote: > > > > On Mon, Apr 28, 2025 at 01:12:38PM +0300, Raag Jadav wrote: > > > > > On Fri, Apr 25, 2025 at 07:36:23PM +0530, Raag Jadav wrote: > > > > > > This series exposes sysfs attributes for BMG PCIe Gen5 > > > > > > downgrade and > > > > > > documents their usage. > > > > > > > > > > Anything I can do to move this forward? > > > > > > > > I almost push it here, but then I noticed that it is > > > > gen5_downgrade. > > > > Hadn't we agreed to follow what spec says so? > > > > > > > > "to then automatically persist the Gen4 downgrade flag in Flash" > > > > "Write Gen4 Downgrade bit to MRC Flash File" > > > > > > > > == Applying  PCIe Gen4 Downgrade == > > > > > > > > Although I see that there are some mentions calling "Gen5 > > > > downgrade", "Gen4 downgrade" seems to be the most used term in > > > > the specs, specially when calling bits and > > > > sections names... > > > > Which is what I followed until we had a change of preference over gen > > definition. > > https://lore.kernel.org/intel-xe/34b33d3135fc24302db2764ce86a641e7c49054f.camel@intel.com/ > > > > > Because of the inconsistencies and our back and forth here and to > > > get prepared > > > for future cases where we might need to downgrade from gen6 to > > > gen5, the current > > > Architecture recommendation is to simply go with > > > > > > so /sys/bus/pci/devices//pcie_gen_downgrade_{status,capable} > > > > I really like Lucas' proposal, which is also consistent with similar > > existing > > attributes. > > > > /sys/bus/pci/devices//auto_link_downgrade_capable > > I'm sorry for the delay in the response, it took a while to get > confirmation. We can go with this one. or with the one you sent > already. Your call. Just let me know that I push the version you tell > and tell the architects to update the spec. I'm okay with either one. But since it was Lucas' idea, let's hear his thoughts. Lucas, can we move forward with auto_link_downgrade_capable? Raag