From b8b6611048b7b57b86fbdc9153649ad4dc52135f Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 11 Mar 2013 05:05:16 +0000 Subject: PCI / ACPI: hold acpi_scan_lock during root bus hotplug During merging the PCI tree with the PM/ACPI tree, Linus noticed that we don't use the same lock using patten about ACPI PCI root as acpiphp. Here apply the same locking patten, and we need to execute acpi_bus_hot_remove_device() via acpi_os_hotplug_execute() as it also holds acpi_scan_lock. [rjw: Changelog] Reported-by: Linus Torvalds Signed-off-by: Yinghai Lu No-objection-from: Bjorn Helgaas Signed-off-by: Rafael J. Wysocki --- drivers/acpi/pci_root.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/acpi/pci_root.c') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 0ac546d5e53f..5ff173066127 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -646,6 +646,7 @@ static void handle_root_bridge_insertion(acpi_handle handle) static void handle_root_bridge_removal(struct acpi_device *device) { + acpi_status status; struct acpi_eject_event *ej_event; ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL); @@ -661,7 +662,9 @@ static void handle_root_bridge_removal(struct acpi_device *device) ej_event->device = device; ej_event->event = ACPI_NOTIFY_EJECT_REQUEST; - acpi_bus_hot_remove_device(ej_event); + status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event); + if (ACPI_FAILURE(status)) + kfree(ej_event); } static void _handle_hotplug_event_root(struct work_struct *work) @@ -676,8 +679,9 @@ static void _handle_hotplug_event_root(struct work_struct *work) handle = hp_work->handle; type = hp_work->type; - root = acpi_pci_find_root(handle); + acpi_scan_lock_acquire(); + root = acpi_pci_find_root(handle); acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); switch (type) { @@ -711,6 +715,7 @@ static void _handle_hotplug_event_root(struct work_struct *work) break; } + acpi_scan_lock_release(); kfree(hp_work); /* allocated in handle_hotplug_event_bridge */ kfree(buffer.pointer); } -- cgit From b8178f130e25c1bdac1c33e0996f1ff6e20ec08e Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Mon, 1 Apr 2013 15:47:39 -0600 Subject: Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus" This reverts commit 8c33f51df406e1a1f7fa4e9b244845b7ebd61fa6. Conflicts: drivers/acpi/pci_root.c This commit broke some pre-1.1 PCIe devices by leaving them with ASPM enabled. Previously, we had disabled ASPM on these devices because many of them don't implement it correctly (per 149e1637). Requesting _OSC control early means that aspm_disabled may be set before we scan the PCI bus and configure link ASPM state. But the ASPM configuration currently skips the check for pre-PCIe 1.1 devices when aspm_disabled is set, like this: acpi_pci_root_add acpi_pci_osc_support if (flags != base_flags) pcie_no_aspm aspm_disabled = 1 pci_acpi_scan_root ... pcie_aspm_init_link_state pcie_aspm_sanity_check if (!aspm_disabled) /* check for pre-PCIe 1.1 device */ Therefore, setting aspm_disabled early means that we leave ASPM enabled on these pre-PCIe 1.1 devices, which is a regression for some devices. The best fix would be to clean up the ASPM init so we can evaluate _OSC before scanning the bug (that way boot-time and hot-add discovery will work the same), but that requires significant rework. For now, we'll just revert the _OSC change as the lowest-risk fix. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=55211 Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki Acked-by: Yinghai Lu CC: stable@vger.kernel.org # v3.8+ --- drivers/acpi/pci_root.c | 76 ++++++++++++++++++++++++------------------------- 1 file changed, 37 insertions(+), 39 deletions(-) (limited to 'drivers/acpi/pci_root.c') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 0ac546d5e53f..c740364d4abe 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -415,7 +415,6 @@ static int acpi_pci_root_add(struct acpi_device *device, struct acpi_pci_root *root; struct acpi_pci_driver *driver; u32 flags, base_flags; - bool is_osc_granted = false; root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL); if (!root) @@ -476,6 +475,30 @@ 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. + */ + + mutex_lock(&acpi_pci_root_lock); + list_add_tail(&root->node, &acpi_pci_roots); + mutex_unlock(&acpi_pci_root_lock); + + /* + * 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) { + printk(KERN_ERR PREFIX + "Bus %04x:%02x not present in PCI namespace\n", + root->segment, (unsigned int)root->secondary.start); + result = -ENODEV; + goto out_del_root; + } + /* Indicate support for various _OSC capabilities. */ if (pci_ext_cfg_avail()) flags |= OSC_EXT_PCI_CONFIG_SUPPORT; @@ -494,6 +517,7 @@ static int acpi_pci_root_add(struct acpi_device *device, flags = base_flags; } } + if (!pcie_ports_disabled && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) { flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL @@ -514,54 +538,28 @@ static int acpi_pci_root_add(struct acpi_device *device, status = acpi_pci_osc_control_set(device->handle, &flags, OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL); if (ACPI_SUCCESS(status)) { - is_osc_granted = true; dev_info(&device->dev, "ACPI _OSC control (0x%02x) granted\n", flags); + if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { + /* + * We have ASPM control, but the FADT indicates + * that it's unsupported. Clear it. + */ + pcie_clear_aspm(root->bus); + } } else { - is_osc_granted = false; dev_info(&device->dev, "ACPI _OSC request failed (%s), " "returned control mask: 0x%02x\n", acpi_format_exception(status), flags); + pr_info("ACPI _OSC control for PCIe not granted, " + "disabling ASPM\n"); + pcie_no_aspm(); } } else { dev_info(&device->dev, - "Unable to request _OSC control " - "(_OSC support mask: 0x%02x)\n", flags); - } - - /* - * TBD: Need PCI interface for enumeration/configuration of roots. - */ - - mutex_lock(&acpi_pci_root_lock); - list_add_tail(&root->node, &acpi_pci_roots); - mutex_unlock(&acpi_pci_root_lock); - - /* - * 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) { - printk(KERN_ERR PREFIX - "Bus %04x:%02x not present in PCI namespace\n", - root->segment, (unsigned int)root->secondary.start); - result = -ENODEV; - goto out_del_root; - } - - /* ASPM setting */ - if (is_osc_granted) { - if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) - pcie_clear_aspm(root->bus); - } else { - pr_info("ACPI _OSC control for PCIe not granted, " - "disabling ASPM\n"); - pcie_no_aspm(); + "Unable to request _OSC control " + "(_OSC support mask: 0x%02x)\n", flags); } pci_acpi_add_bus_pm_notifier(device, root->bus); -- cgit