From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: "Rafael J. Wysocki" To: Bjorn Helgaas Cc: Rajat Jain , "linux-pci@vger.kernel.org" , Yinghai Lu , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/4] PCI: pciehp: Clean up debug logging Date: Thu, 18 Jun 2015 23:52:49 +0200 Message-ID: <1650350.VG8hpWuxzd@vostro.rjw.lan> In-Reply-To: References: <20150618161207.32739.62577.stgit@bhelgaas-glaptop2.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: On Thursday, June 18, 2015 04:22:53 PM Bjorn Helgaas wrote: > [+cc Rafael] > > On Thu, Jun 18, 2015 at 1:08 PM, Rajat Jain wrote: > > On Thu, Jun 18, 2015 at 11:01 AM, Bjorn Helgaas wrote: > >> On Thu, Jun 18, 2015 at 12:27 PM, Rajat Jain wrote: > >>> Hi, > >>> > >>> On Thu, Jun 18, 2015 at 9:12 AM, Bjorn Helgaas wrote: > >>>> The pciehp debug logging is overly verbose and often redundant. Almost all > >>>> of the information printed by dbg_ctrl() is also printed by the normal PCI > >>>> core enumeration code and by pcie_init(). > >>>> > >>>> Remove the redundant debug info. > >>>> > >>>> When claiming a pciehp bridge, we print the slot characteristics, e.g., > >>>> > >>>> Slot #6 AttnBtn- AttnInd- PwrInd- PwrCtrl- MRL- Interlock- NoCompl+ LLActRep+ > >>>> > >>>> Add the Hot-Plug Capable and Hot-Plug Surprise bits to this information, > >>> > >>> If the slot is not hotplug capable. then pciehp wouldn't claim it in > >>> the first place. > >>> > >>> So printing of "hotplug capable" may really not be needed.. > >> > >> Yes, I did think about that, and you're right that it probably isn't > >> needed. But the criteria for claiming a slot and deciding whether > >> acpiphp or pciehp should manage it are not 100% clear yet, so I > >> figured it wouldn't hurt to be a bit more transparent. > > > > Sounds right. > > > > Reviewed-by : Rajat Jain > > > > Side note: To clarify when and why the slot was claimed by pciehp or > > acpihp, do you think we need some mumbling / logging in > > acpi_pci_detect_ejectable() or pciehp_acpi_slot_detection_check()? > > Maybe so (but I haven't added anything). > > My intuition is that acpiphp and pciehp are not really symmetric. I > think pciehp should claim PCIe downstream ports (Root Ports and > Downstream Ports) when _OSC has granted us control. > > But it doesn't seem like acpiphp should decide whether to claim > certain devices based on whether they have _ADR, _EJ0, _RMV, etc. But it doesn't do that, does it? > Shouldn't it just be integrated with the ACPI core so it can field > notifications from the platform, no matter what methods are present, > and even if pciehp has claimed a bridge in that scope? That's how it is implemented today AFAICS. Thanks, Rafael