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[209.132.180.67]) by mx.google.com with ESMTP id b18si1872536edc.390.2019.10.25.13.56.23; Fri, 25 Oct 2019 13:56:46 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=NInZl2n0; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726893AbfJYTPk (ORCPT + 99 others); Fri, 25 Oct 2019 15:15:40 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:38540 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725897AbfJYTPh (ORCPT ); Fri, 25 Oct 2019 15:15:37 -0400 Received: by mail-pl1-f193.google.com with SMTP id w8so1759441plq.5; Fri, 25 Oct 2019 12:15:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=kD+tjQBMZ/Kzwr3+FKFta1lL67FtvDA1KxEZTDOTl4g=; b=NInZl2n0t1/gDeExYL1/6yisd3c76oTrodWsybCBjzFNHXvRAnp0Pte+mvw41k9r8l RcmhKAC9J5xZlCFgK+NnYmlkjz6sKwY8X2WhbZaid6oy9m7YRKKBFaNRYR8VhCt4JTMP r/kqjo+jqbCFZcQxE/aahJJJmPDhAjY6yXQb/Yf5BKi0q6X1354LcotBRpVRdDcPVG9t Dn9ImqfYsF4bfLUt2hOrnpLyjiFyVPPzZj8oImWavp2Vov4382BMN8Dlyt185eBblw0o yzNFeoc1NWwB8H03DeZ06WlD5lYYbXT2Du3xvpI8YflZhHdnr67rHirhEtQHJZgy2egA yQIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=kD+tjQBMZ/Kzwr3+FKFta1lL67FtvDA1KxEZTDOTl4g=; b=Fw3NyqPmCgevsNfL6tOg+GDM1Ml5vYVBOLCJSYxto4/K91JyX6T3S9yH1eWEKRparr WNV+KSh3+L4ssaL6J0YehrzJ4ituYW7Yus1KWwUGKboOTfcrpU4Gca4Ij9jCCdNSO4Yv QyXAbwiHKboq9cFbz0J6PA6L4zExlosEfmDKEhnPcl3NPx/n5ZQgd1RP0oX6mKMFTL0y ahf8RSfDQvYqOv7aBFn58I1xbqDf00k9ciCST6FhVXFX3ZAzuBxMsWWPL2QWj5jEIizh 3GAV+Q18H27PRA5Re4qYGcysOFfbzp8rVCXMuGWOqJE2TJzXeyiZA+l6ic7EZssx6WGQ VZXA== X-Gm-Message-State: APjAAAWNpEvls8jxYvi8IZ1JAbl8nUI0GpUCGdFYbV63DNt9IvRjYNxf fXpTCSUPMjwAe9Ba/mlzGH7K24l65xD7E1iDaNf8X9Y49Mk= X-Received: by 2002:a17:902:9881:: with SMTP id s1mr5731612plp.18.1572030936171; Fri, 25 Oct 2019 12:15:36 -0700 (PDT) MIME-Version: 1.0 References: <20191025190047.38130-1-stuart.w.hayes@gmail.com> <20191025190047.38130-2-stuart.w.hayes@gmail.com> In-Reply-To: <20191025190047.38130-2-stuart.w.hayes@gmail.com> From: Andy Shevchenko Date: Fri, 25 Oct 2019 22:15:24 +0300 Message-ID: Subject: Re: [PATCH v4 1/3] PCI: pciehp: Add support for disabling in-band presence To: Stuart Hayes Cc: Bjorn Helgaas , Austin Bolen , Keith Busch , Alexandru Gagniuc , "Rafael J . Wysocki" , Mika Westerberg , "Gustavo A . R . Silva" , Sinan Kaya , Oza Pawandeep , linux-pci@vger.kernel.org, Linux Kernel Mailing List , Lukas Wunner Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 25, 2019 at 10:00 PM Stuart Hayes wrote: > > From: Alexandru Gagniuc > > The presence detect state (PDS) is normally a logical or of in-band and > out-of-band presence. As of PCIe 4.0, there is the option to disable > in-band presence so that the PDS bit always reflects the state of the > out-of-band presence. > > The recommendation of the PCIe spec is to disable in-band presence > whenever supported. > FWIW, Reviewed-by: Andy Shevchenko > Signed-off-by: Alexandru Gagniuc > --- > drivers/pci/hotplug/pciehp.h | 1 + > drivers/pci/hotplug/pciehp_hpc.c | 9 ++++++++- > include/uapi/linux/pci_regs.h | 2 ++ > 3 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h > index 654c972b8ea0..27e4cd6529b0 100644 > --- a/drivers/pci/hotplug/pciehp.h > +++ b/drivers/pci/hotplug/pciehp.h > @@ -83,6 +83,7 @@ struct controller { > struct pcie_device *pcie; > > u32 slot_cap; /* capabilities and quirks */ > + unsigned int inband_presence_disabled:1; > > u16 slot_ctrl; /* control register access */ > struct mutex ctrl_lock; > diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c > index 1a522c1c4177..dc109d521f30 100644 > --- a/drivers/pci/hotplug/pciehp_hpc.c > +++ b/drivers/pci/hotplug/pciehp_hpc.c > @@ -811,7 +811,7 @@ static inline void dbg_ctrl(struct controller *ctrl) > struct controller *pcie_init(struct pcie_device *dev) > { > struct controller *ctrl; > - u32 slot_cap, link_cap; > + u32 slot_cap, slot_cap2, link_cap; > u8 poweron; > struct pci_dev *pdev = dev->port; > struct pci_bus *subordinate = pdev->subordinate; > @@ -869,6 +869,13 @@ struct controller *pcie_init(struct pcie_device *dev) > FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC), > pdev->broken_cmd_compl ? " (with Cmd Compl erratum)" : ""); > > + pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP2, &slot_cap2); > + if (slot_cap2 & PCI_EXP_SLTCAP2_IBPD) { > + pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_IBPD_DISABLE, > + PCI_EXP_SLTCTL_IBPD_DISABLE); > + ctrl->inband_presence_disabled = 1; > + } > + > /* > * If empty slot's power status is on, turn power off. The IRQ isn't > * requested yet, so avoid triggering a notification with this command. > diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h > index 29d6e93fd15e..ea1cf9546e4d 100644 > --- a/include/uapi/linux/pci_regs.h > +++ b/include/uapi/linux/pci_regs.h > @@ -604,6 +604,7 @@ > #define PCI_EXP_SLTCTL_PWR_OFF 0x0400 /* Power Off */ > #define PCI_EXP_SLTCTL_EIC 0x0800 /* Electromechanical Interlock Control */ > #define PCI_EXP_SLTCTL_DLLSCE 0x1000 /* Data Link Layer State Changed Enable */ > +#define PCI_EXP_SLTCTL_IBPD_DISABLE 0x4000 /* In-band PD disable */ > #define PCI_EXP_SLTSTA 26 /* Slot Status */ > #define PCI_EXP_SLTSTA_ABP 0x0001 /* Attention Button Pressed */ > #define PCI_EXP_SLTSTA_PFD 0x0002 /* Power Fault Detected */ > @@ -676,6 +677,7 @@ > #define PCI_EXP_LNKSTA2 50 /* Link Status 2 */ > #define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 52 /* v2 endpoints with link end here */ > #define PCI_EXP_SLTCAP2 52 /* Slot Capabilities 2 */ > +#define PCI_EXP_SLTCAP2_IBPD 0x0001 /* In-band PD Disable Supported */ > #define PCI_EXP_SLTCTL2 56 /* Slot Control 2 */ > #define PCI_EXP_SLTSTA2 58 /* Slot Status 2 */ > > -- > 2.18.1 > -- With Best Regards, Andy Shevchenko