On Mon, Sep 23, 2013 at 4:33 PM, <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> The patch below does not apply to the 3.10-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
This patch and Rafael's recent acpiphp changes fix hotplug issues that
have been reported by many people:
https://bugzilla.kernel.org/show_bug.cgi?id=16119 jmb38x
recognized and works only if a card is plugged in during boot
https://bugzilla.kernel.org/show_bug.cgi?id=54981 ExpressCard
hotplug fails except with pcie_ports=native
https://bugzilla.kernel.org/show_bug.cgi?id=60736 acpiphp and
pciehp not working together on Thinkpad X200s
I don't know exactly which of Rafael's changes would be required or
how big they are, but I definitely support backporting this stuff if
it's feasible.
> ------------------ original commit in Linus's tree ------------------
>
> From 3dc48af310709b85d07c8b0d3aa8f1ead02829d3 Mon Sep 17 00:00:00 2001
> From: Neil Horman <nhorman@xxxxxxxxxxxxx>
> Date: Thu, 29 Aug 2013 16:17:05 -0400
> Subject: [PATCH] PCI/ACPI: Fix _OSC ordering to allow PCIe hotplug use when
> available
>
> This fixes the problem of acpiphp claiming slots that should be managed
> by pciehp, which may keep ExpressCard slots from working.
>
> The acpiphp driver claims PCIe slots unless the BIOS has granted us
> control of PCIe native hotplug via _OSC. Prior to v3.10, the acpiphp
> .add method (add_bridge()) was always called *after* we had requested
> native hotplug control with _OSC.
>
> But after 3b63aaa70e ("PCI: acpiphp: Do not use ACPI PCI subdriver
> mechanism"), which appeared in v3.10, acpiphp initialization is done
> during the bus scan via the pcibios_add_bus() hook, and this happens
> *before* we request native hotplug control.
>
> Therefore, acpiphp doesn't know yet whether the BIOS will grant control,
> and it claims slots that we should be handling with native hotplug.
>
> This patch requests native hotplug control earlier, so we know whether
> the BIOS granted it to us before we initialize acpiphp.
>
> To avoid reintroducing the ASPM issue fixed by b8178f130e ('Revert
> "PCI/ACPI: Request _OSC control before scanning PCI root bus"'), we run
> _OSC earlier but defer the actual ASPM calls until after the bus scan is
> complete.
>
> Tested successfully by myself.
>
> [bhelgaas: changelog, mark for stable]
> Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60736
> Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Acked-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx # v3.10+
> CC: Len Brown <lenb@xxxxxxxxxx>
> CC: "Rafael J. Wysocki" <rjw@xxxxxxx>
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 59178393..a67853e3 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -378,6 +378,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
> struct acpi_pci_root *root;
> u32 flags, base_flags;
> acpi_handle handle = device->handle;
> + bool no_aspm = false, clear_aspm = false;
>
> root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
> if (!root)
> @@ -437,27 +438,6 @@ static int acpi_pci_root_add(struct acpi_device *device,
> flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
> acpi_pci_osc_support(root, flags);
>
> - /*
> - * TBD: Need PCI interface for enumeration/configuration of roots.
> - */
> -
> - /*
> - * Scan the Root Bridge
> - * --------------------
> - * Must do this prior to any attempt to bind the root device, as the
> - * PCI namespace does not get created until this call is made (and
> - * thus the root bridge's pci_dev does not exist).
> - */
> - root->bus = pci_acpi_scan_root(root);
> - if (!root->bus) {
> - dev_err(&device->dev,
> - "Bus %04x:%02x not present in PCI namespace\n",
> - root->segment, (unsigned int)root->secondary.start);
> - result = -ENODEV;
> - goto end;
> - }
> -
> - /* Indicate support for various _OSC capabilities. */
> if (pci_ext_cfg_avail())
> flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
> if (pcie_aspm_support_enabled()) {
> @@ -471,7 +451,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
> if (ACPI_FAILURE(status)) {
> dev_info(&device->dev, "ACPI _OSC support "
> "notification failed, disabling PCIe ASPM\n");
> - pcie_no_aspm();
> + no_aspm = true;
> flags = base_flags;
> }
> }
> @@ -503,7 +483,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
> * We have ASPM control, but the FADT indicates
> * that it's unsupported. Clear it.
> */
> - pcie_clear_aspm(root->bus);
> + clear_aspm = true;
> }
> } else {
> dev_info(&device->dev,
> @@ -512,7 +492,14 @@ static int acpi_pci_root_add(struct acpi_device *device,
> acpi_format_exception(status), flags);
> dev_info(&device->dev,
> "ACPI _OSC control for PCIe not granted, disabling ASPM\n");
> - pcie_no_aspm();
> + /*
> + * We want to disable ASPM here, but aspm_disabled
> + * needs to remain in its state from boot so that we
> + * properly handle PCIe 1.1 devices. So we set this
> + * flag here, to defer the action until after the ACPI
> + * root scan.
> + */
> + no_aspm = true;
> }
> } else {
> dev_info(&device->dev,
> @@ -520,6 +507,33 @@ static int acpi_pci_root_add(struct acpi_device *device,
> "(_OSC support mask: 0x%02x)\n", flags);
> }
>
> + /*
> + * TBD: Need PCI interface for enumeration/configuration of roots.
> + */
> +
> + /*
> + * Scan the Root Bridge
> + * --------------------
> + * Must do this prior to any attempt to bind the root device, as the
> + * PCI namespace does not get created until this call is made (and
> + * thus the root bridge's pci_dev does not exist).
> + */
> + root->bus = pci_acpi_scan_root(root);
> + if (!root->bus) {
> + dev_err(&device->dev,
> + "Bus %04x:%02x not present in PCI namespace\n",
> + root->segment, (unsigned int)root->secondary.start);
> + result = -ENODEV;
> + goto end;
> + }
> +
> + if (clear_aspm) {
> + dev_info(&device->dev, "Disabling ASPM (FADT indicates it is unsupported)\n");
> + pcie_clear_aspm(root->bus);
> + }
> + if (no_aspm)
> + pcie_no_aspm();
> +
> pci_acpi_add_bus_pm_notifier(device, root->bus);
> if (device->wakeup.flags.run_wake)
> device_set_run_wake(root->bus->bridge, true);
>
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