From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752289AbeFETLr (ORCPT ); Tue, 5 Jun 2018 15:11:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:34140 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752035AbeFETLp (ORCPT ); Tue, 5 Jun 2018 15:11:45 -0400 Date: Tue, 5 Jun 2018 14:11:42 -0500 From: Bjorn Helgaas To: Ryankao Cc: Kai Heng Feng , "jrg.otte@gmail.com" , David Miller , Hayes Wang , "hkallweit1@gmail.com" , "romieu@fr.zoreil.com" , Linux Netdev List , Linux Kernel Mailing List , Hau , linux-pci@vger.kernel.org Subject: Re: [PATCH] r8169: Reinstate ALDPS and ASPM support Message-ID: <20180605191142.GA214338@bhelgaas-glaptop.roam.corp.google.com> References: <20180605045812.17977-1-kai.heng.feng@canonical.com> <9D9E2AF1-CD59-425B-85E9-DB89D620CA67@canonical.com> <20180605172805.GD30381@bhelgaas-glaptop.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180605172805.GD30381@bhelgaas-glaptop.roam.corp.google.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [+cc linux-pci] On Tue, Jun 05, 2018 at 12:28:05PM -0500, Bjorn Helgaas wrote: > On Tue, Jun 05, 2018 at 06:34:09AM +0000, Ryankao wrote: > > Add realtek folk Hau > > > > -----Original Message----- > > From: Kai Heng Feng [mailto:kai.heng.feng@canonical.com] > > Sent: Tuesday, June 05, 2018 1:02 PM > > To: jrg.otte@gmail.com > > Cc: David Miller ; Hayes Wang ; hkallweit1@gmail.com; romieu@fr.zoreil.com; Linux Netdev List ; Linux Kernel Mailing List ; Ryankao > > Subject: Re: [PATCH] r8169: Reinstate ALDPS and ASPM support > > > > Hi Jörg Otte, > > > > Can you give this patch a try? > > > > Since you are the only one that reported ALDPS/ASPM regression, > > > > And I think this patch should solve the issue you had [1]. > > > > Hopefully we don't need to go down the rabbit hole of blacklist/whitelist... > > > > Kai-Heng > > > > [1] https://lkml.org/lkml/2013/1/5/36 > > I have no idea what ALDPS is. It's not mentioned in the PCIe spec, so > presumably it's some Realtek-specific thing. ASPM is a generic PCIe > thing. Changes to these two things should be in separate patches so > they don't get tangled up. > > > > On Jun 5, 2018, at 12:58 PM, Kai-Heng Feng > > > > > > wrote: > > > > > > This patch reinstate ALDPS and ASPM support on r8169. > > > > > > On some Intel platforms, ASPM support on r8169 is the key factor to > > > let Package C-State achieve PC8. Without ASPM support, the deepest > > > Package C-State can hit is PC3. PC8 can save additional ~3W in > > > comparison with PC3. > > > > > > This patch is from Realtek. > > > > > > Fixes: e0c075577965 ("r8169: enable ALDPS for power saving") > > > Fixes: d64ec841517a ("r8169: enable internal ASPM and clock request > > > settings") > > > > +3507,15 @@ static void rtl8168e_1_hw_phy_config(struct > > > rtl8169_private *tp) > > > rtl_writephy(tp, 0x0d, 0x4007); > > > rtl_writephy(tp, 0x0e, 0x0000); > > > rtl_writephy(tp, 0x0d, 0x0000); > > > + > > > + /* Check ALDPS bit, disable it if enabled */ > > > + rtl_writephy(tp, 0x1f, 0x0000); > > > + if (enable_aldps) > > > + rtl_w0w1_phy(tp, 0x15, 0x1000, 0x0000); > > > + else if (rtl_readphy(tp, 0x15) & 0x1000) > > > + rtl_w0w1_phy(tp, 0x15, 0x0000, 0x1000); > > There's a lot of repetition of this code with minor variations. You > could probably factor it out and make it more concise and more > readable. > > > > +static void rtl8169_check_link_status(struct net_device *dev, > > > + struct rtl8169_private *tp) { > > > + struct device *d = tp_to_dev(tp); > > > + > > > + if (tp->link_ok(tp)) { > > > + rtl_link_chg_patch(tp); > > > + /* This is to cancel a scheduled suspend if there's one. */ > > > + if (pm_request_resume(d)) > > > + _rtl_reset_work(tp); > > > + netif_carrier_on(dev); > > > + if (net_ratelimit()) > > > + netif_info(tp, ifup, dev, "link up\n"); > > > + } else { > > > + netif_carrier_off(dev); > > > + netif_info(tp, ifdown, dev, "link down\n"); > > > + pm_runtime_idle(d); > > > + } > > > +} > > This function apparently just got moved around without changing > anything. That's fine, but the move should be in a separate patch to > make the real changes easier to review. > > > > @@ -7649,8 +7757,12 @@ static int rtl_init_one(struct pci_dev *pdev, > > > const struct pci_device_id *ent) > > > > > > /* disable ASPM completely as that cause random device stop working > > > * problems as well as full system hangs for some PCIe devices users */ > > > - pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1 | > > > - PCIE_LINK_STATE_CLKPM); > > > + if (!enable_aspm) { > > > + pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | > > > + PCIE_LINK_STATE_L1 | > > > + PCIE_LINK_STATE_CLKPM); > > > + netif_info(tp, probe, dev, "ASPM disabled\n"); > > > + } > > ASPM is a generic PCIe feature that should be configured by the PCI > core without any help from the device driver. > > If code in the driver is needed, that means either the PCI core is > doing it wrong and we should fix it there, or the device is broken and > the driver is working around the erratum. > > If this is an erratum, you should include details about exactly what's > broken and (ideally) a URL to the published erratum. Otherwise this > is just unmaintainable black magic and likely to be broken by future > ASPM changes in the PCI core. > > ASPM configuration is done by the PCI core before drivers are bound to > the device. If you need device-specific workarounds, they should > probably be in quirks so they're done before the core does that ASPM > configuration. > > > > /* enable device (incl. PCI PM wakeup and hotplug setup) */ > > > rc = pcim_enable_device(pdev); > > > -- > > > 2.17.0 > > > > ------Please consider the environment before printing this e-mail.