On Tue, May 19, 2015 at 03:27:58PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Jarod Wilson reports that the expresscard hotplug setup doesn't work > on HP ZBook G2. The problem turns out to be the ACPI-based "slot > detection" code called from pciehp_probe() which tries to use some > questionable heuristics based on what ACPI objects are present for > the PCIe port device at hand to figure out whether or not to register > a hotplug slot for that port. > > That code is used if there is at least one PCIe port having an ACPI > device configuration object related to hotplug (such as _EJ0 or _RMV) > and the Thunderbolt port on the affected machine has _RMV. Of course, > Thunderbolt and PCIe native hotplug need not be mutually exclusive > (as they aren't on the machine in question), so that rule is simply > incorrect. > > Moreover, the ACPI-based "slot detection" check does not add any > value if pciehp_probe() is called at all and the service type of the > device object it has been called for is PCIE_PORT_SERVICE_HP, because > PCIe hotplug services are only registered if the _OSC handshake in > acpi_pci_root_add() allows the kernel to control the PCIe native > hotplug feature. No more checks need to be carried out to decide > whether or not to register a native PCIe hotlug slot in that case. > > For the above reasons, make pciehp_probe() check if it has been > called for the right service type and drop the pointless ACPI-based > "slot detection" check from it. Also remove the entire code whose > only user is that check (the entire pciehp_acpi.c file goes away > as a result) and drop function headers related to it from the > internal PCIeHP header file. > > Link: http://marc.info/?t=143163219300002&r=1&w=2 > Link: https://bugzilla.kernel.org/show_bug.cgi?id=98581 > Reported-by: Jarod Wilson <jarod@xxxxxxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> This is awesome! Applied to pci/hotplug for v4.2, with Jarod's reviewed/tested-by. I suspect a lot of this stuff dates back to when acpiphp and pciehp could be modules, and one driver really couldn't know whether the other was up to. In any event, I think it will be much more predictable and maintainable now. Bjorn > --- > > Changes in Makefile were missing from the previous version. > > Bjorn, that's -stable material I think. It should be applicable at least > since commit 5ba113f7c4fb (PCI: acpiphp: Handle PCIe ports without native > hotplug capability) that was shipped in 3.10. > > Thanks! > > --- > drivers/pci/hotplug/Makefile | 3 > drivers/pci/hotplug/pciehp.h | 17 ---- > drivers/pci/hotplug/pciehp_acpi.c | 137 -------------------------------------- > drivers/pci/hotplug/pciehp_core.c | 10 -- > 4 files changed, 3 insertions(+), 164 deletions(-) > > Index: linux-pm/drivers/pci/hotplug/pciehp_core.c > =================================================================== > --- linux-pm.orig/drivers/pci/hotplug/pciehp_core.c > +++ linux-pm/drivers/pci/hotplug/pciehp_core.c > @@ -248,12 +248,9 @@ static int pciehp_probe(struct pcie_devi > struct slot *slot; > u8 occupied, poweron; > > - if (pciehp_force) > - dev_info(&dev->device, > - "Bypassing BIOS check for pciehp use on %s\n", > - pci_name(dev->port)); > - else if (pciehp_acpi_slot_detection_check(dev->port)) > - goto err_out_none; > + /* If this is not a "hotplug" service, we have no business here. */ > + if (dev->service != PCIE_PORT_SERVICE_HP) > + return -ENODEV; > > if (!dev->port->subordinate) { > /* Can happen if we run out of bus numbers during probe */ > @@ -366,7 +363,6 @@ static int __init pcied_init(void) > { > int retval = 0; > > - pciehp_firmware_init(); > retval = pcie_port_service_register(&hpdriver_portdrv); > dbg("pcie_port_service_register = %d\n", retval); > info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); > Index: linux-pm/drivers/pci/hotplug/pciehp_acpi.c > =================================================================== > --- linux-pm.orig/drivers/pci/hotplug/pciehp_acpi.c > +++ /dev/null > @@ -1,137 +0,0 @@ > -/* > - * ACPI related functions for PCI Express Hot Plug driver. > - * > - * Copyright (C) 2008 Kenji Kaneshige > - * Copyright (C) 2008 Fujitsu Limited. > - * > - * All rights reserved. > - * > - * This program is free software; you can redistribute it and/or modify > - * it under the terms of the GNU General Public License as published by > - * the Free Software Foundation; either version 2 of the License, or (at > - * your option) any later version. > - * > - * This program is distributed in the hope that it will be useful, but > - * WITHOUT ANY WARRANTY; without even the implied warranty of > - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or > - * NON INFRINGEMENT. See the GNU General Public License for more > - * details. > - * > - * You should have received a copy of the GNU General Public License > - * along with this program; if not, write to the Free Software > - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. > - * > - */ > - > -#include <linux/acpi.h> > -#include <linux/pci.h> > -#include <linux/pci_hotplug.h> > -#include <linux/slab.h> > -#include <linux/module.h> > -#include "pciehp.h" > - > -#define PCIEHP_DETECT_PCIE (0) > -#define PCIEHP_DETECT_ACPI (1) > -#define PCIEHP_DETECT_AUTO (2) > -#define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_AUTO > - > -struct dummy_slot { > - u32 number; > - struct list_head list; > -}; > - > -static int slot_detection_mode; > -static char *pciehp_detect_mode; > -module_param(pciehp_detect_mode, charp, 0444); > -MODULE_PARM_DESC(pciehp_detect_mode, > - "Slot detection mode: pcie, acpi, auto\n" > - " pcie - Use PCIe based slot detection\n" > - " acpi - Use ACPI for slot detection\n" > - " auto(default) - Auto select mode. Use acpi option if duplicate\n" > - " slot ids are found. Otherwise, use pcie option\n"); > - > -int pciehp_acpi_slot_detection_check(struct pci_dev *dev) > -{ > - if (slot_detection_mode != PCIEHP_DETECT_ACPI) > - return 0; > - if (acpi_pci_detect_ejectable(ACPI_HANDLE(&dev->dev))) > - return 0; > - return -ENODEV; > -} > - > -static int __init parse_detect_mode(void) > -{ > - if (!pciehp_detect_mode) > - return PCIEHP_DETECT_DEFAULT; > - if (!strcmp(pciehp_detect_mode, "pcie")) > - return PCIEHP_DETECT_PCIE; > - if (!strcmp(pciehp_detect_mode, "acpi")) > - return PCIEHP_DETECT_ACPI; > - if (!strcmp(pciehp_detect_mode, "auto")) > - return PCIEHP_DETECT_AUTO; > - warn("bad specifier '%s' for pciehp_detect_mode. Use default\n", > - pciehp_detect_mode); > - return PCIEHP_DETECT_DEFAULT; > -} > - > -static int __initdata dup_slot_id; > -static int __initdata acpi_slot_detected; > -static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots); > - > -/* Dummy driver for duplicate name detection */ > -static int __init dummy_probe(struct pcie_device *dev) > -{ > - u32 slot_cap; > - acpi_handle handle; > - struct dummy_slot *slot, *tmp; > - struct pci_dev *pdev = dev->port; > - > - pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap); > - slot = kzalloc(sizeof(*slot), GFP_KERNEL); > - if (!slot) > - return -ENOMEM; > - slot->number = (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19; > - list_for_each_entry(tmp, &dummy_slots, list) { > - if (tmp->number == slot->number) > - dup_slot_id++; > - } > - list_add_tail(&slot->list, &dummy_slots); > - handle = ACPI_HANDLE(&pdev->dev); > - if (!acpi_slot_detected && acpi_pci_detect_ejectable(handle)) > - acpi_slot_detected = 1; > - return -ENODEV; /* dummy driver always returns error */ > -} > - > -static struct pcie_port_service_driver __initdata dummy_driver = { > - .name = "pciehp_dummy", > - .port_type = PCIE_ANY_PORT, > - .service = PCIE_PORT_SERVICE_HP, > - .probe = dummy_probe, > -}; > - > -static int __init select_detection_mode(void) > -{ > - struct dummy_slot *slot, *tmp; > - > - if (pcie_port_service_register(&dummy_driver)) > - return PCIEHP_DETECT_ACPI; > - pcie_port_service_unregister(&dummy_driver); > - list_for_each_entry_safe(slot, tmp, &dummy_slots, list) { > - list_del(&slot->list); > - kfree(slot); > - } > - if (acpi_slot_detected && dup_slot_id) > - return PCIEHP_DETECT_ACPI; > - return PCIEHP_DETECT_PCIE; > -} > - > -void __init pciehp_acpi_slot_detection_init(void) > -{ > - slot_detection_mode = parse_detect_mode(); > - if (slot_detection_mode != PCIEHP_DETECT_AUTO) > - goto out; > - slot_detection_mode = select_detection_mode(); > -out: > - if (slot_detection_mode == PCIEHP_DETECT_ACPI) > - info("Using ACPI for slot detection.\n"); > -} > Index: linux-pm/drivers/pci/hotplug/pciehp.h > =================================================================== > --- linux-pm.orig/drivers/pci/hotplug/pciehp.h > +++ linux-pm/drivers/pci/hotplug/pciehp.h > @@ -167,21 +167,4 @@ static inline const char *slot_name(stru > return hotplug_slot_name(slot->hotplug_slot); > } > > -#ifdef CONFIG_ACPI > -#include <linux/pci-acpi.h> > - > -void __init pciehp_acpi_slot_detection_init(void); > -int pciehp_acpi_slot_detection_check(struct pci_dev *dev); > - > -static inline void pciehp_firmware_init(void) > -{ > - pciehp_acpi_slot_detection_init(); > -} > -#else > -#define pciehp_firmware_init() do {} while (0) > -static inline int pciehp_acpi_slot_detection_check(struct pci_dev *dev) > -{ > - return 0; > -} > -#endif /* CONFIG_ACPI */ > #endif /* _PCIEHP_H */ > Index: linux-pm/drivers/pci/hotplug/Makefile > =================================================================== > --- linux-pm.orig/drivers/pci/hotplug/Makefile > +++ linux-pm/drivers/pci/hotplug/Makefile > @@ -61,9 +61,6 @@ pciehp-objs := pciehp_core.o \ > pciehp_ctrl.o \ > pciehp_pci.o \ > pciehp_hpc.o > -ifdef CONFIG_ACPI > -pciehp-objs += pciehp_acpi.o > -endif > > shpchp-objs := shpchp_core.o \ > shpchp_ctrl.o \ > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
