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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2133FC43613 for ; Mon, 24 Jun 2019 11:57:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F36802133F for ; Mon, 24 Jun 2019 11:57:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727556AbfFXL5B (ORCPT ); Mon, 24 Jun 2019 07:57:01 -0400 Received: from mga11.intel.com ([192.55.52.93]:48688 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726721AbfFXL5B (ORCPT ); Mon, 24 Jun 2019 07:57:01 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Jun 2019 04:57:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,412,1557212400"; d="scan'208";a="161598821" Received: from eyasman-mobl.ger.corp.intel.com (HELO [10.249.90.21]) ([10.249.90.21]) by fmsmga008.fm.intel.com with ESMTP; 24 Jun 2019 04:56:59 -0700 Subject: Re: [Intel-wired-lan] Opportunistic S0ix blocked by e1000e when ethernet is in use To: Kai-Heng Feng , jeffrey.t.kirsher@intel.com Cc: intel-wired-lan@lists.osuosl.org, Anthony Wong , linux-kernel References: <074E1145-A512-4835-9A6D-8FB6634DBD3C@canonical.com> From: "Neftin, Sasha" Message-ID: <95f88f45-fd6c-52e4-de8c-2db1b4c6c04e@intel.com> Date: Mon, 24 Jun 2019 14:56:58 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/24/2019 10:03, Kai-Heng Feng wrote: > Hi Jeffrey, > > at 19:08, Kai-Heng Feng wrote: > >> Hi Jeffrey, >> >> There are several platforms that uses e1000e can’t enter Opportunistic >> S0ix (PC10) when the ethernet has a link partner. >> >> This behavior also exits in out-of-tree e1000e driver 3.4.2.1, but >> seems like 3.4.2.3 fixes the issue. >> >> A quick diff between the two versions shows that this code section may >> be our solution: >> >>         /* Read from EXTCNF_CTRL in e1000_acquire_swflag_ich8lan function >>          * may occur during global reset and cause system hang. >>          * Configuration space access creates the needed delay. >>          * Write to E1000_STRAP RO register >> E1000_PCI_VENDOR_ID_REGISTER value >>          * insures configuration space read is done before global reset. >>          */ >>         pci_read_config_word(hw->adapter->pdev, >> E1000_PCI_VENDOR_ID_REGISTER, >>                              &pci_cfg); >>         ew32(STRAP, pci_cfg); >>         e_dbg("Issuing a global reset to ich8lan\n"); >>         ew32(CTRL, (ctrl | E1000_CTRL_RST)); >>         /* cannot issue a flush here because it hangs the hardware */ >>         msleep(20); >> >>         /* Configuration space access improve HW level time sync >> mechanism. >>          * Write to E1000_STRAP RO register E1000_PCI_VENDOR_ID_REGISTER >>          * value to insure configuration space read is done >>          * before any access to mac register. >>          */ >>         pci_read_config_word(hw->adapter->pdev, >> E1000_PCI_VENDOR_ID_REGISTER, >>                              &pci_cfg); >>         ew32(STRAP, pci_cfg); > > Turns out the "extra sauce” is not this part, it’s called “Dynamic LTR > support”. > >> >> Is there any plan to support this in the upstream kernel? > > Is there any plan to support Dynamic LTR in upstream e1000e? > Dynamic LTR is not stable solution. So, we can not put this solution to upstream. I hope we will be able to fix this in HW for a future projects. S0ix support is under discussion with our architecture. We will try enable S0ix in our e1000e OOT driver as first step. > Kai-Heng > >> >> Kai-Heng > > > _______________________________________________ > Intel-wired-lan mailing list > Intel-wired-lan@osuosl.org > https://lists.osuosl.org/mailman/listinfo/intel-wired-lan Thanks Sasha