Alex Chiang wrote:
> * Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>:
>> There is a problem that some non hot-pluggable PCIe slots are detected
>> as hot-pluggable by pciehp on some platforms. The immediate cause of
>> this problem is that hot-plug capable bit in the Slot Capabilities
>> register is set even for non hot-pluggable slots on those platforms.
>> It seems a BIOS/hardware problem, but we need workaround about that.
>>
>> Some of those platforms define hot-pluggable PCIe slots on ACPI
>> namespace properly, while hot-plug capable bit in the Slot
>> Capabilities register is set improperly. So using ACPI namespace
>> information in pciehp to detect PCIe hot-pluggable slots would be a
>> workaround.
>>
>> This patch adds 'pciehp_detect_mode' module option. When 'acpi' is
>> specified, pciehp uses ACPI namespace information to detect PCIe
>> hot-pluggable slots.
>>
>> Signed-off-by: Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>
>>
>> ---
>> drivers/pci/hotplug/Makefile | 3 +
>> drivers/pci/hotplug/pciehp.h | 15 ++++-
>> drivers/pci/hotplug/pciehp_acpi.c | 114 ++++++++++++++++++++++++++++++++++++++
>> drivers/pci/hotplug/pciehp_core.c | 1
>> 4 files changed, 132 insertions(+), 1 deletion(-)
>>
>> Index: 20081212/drivers/pci/hotplug/pciehp.h
>> ===================================================================
>> --- 20081212.orig/drivers/pci/hotplug/pciehp.h
>> +++ 20081212/drivers/pci/hotplug/pciehp.h
>> @@ -220,11 +220,23 @@ struct hpc_ops {
>> #include <acpi/actypes.h>
>> #include <linux/pci-acpi.h>
>>
>> +extern void __init pciehp_acpi_slot_detection_init(void);
>> +extern int pciehp_acpi_slot_detection_check(struct pci_dev *dev);
>> +
>> +static inline void pciehp_firmware_init(void)
>> +{
>> + pciehp_acpi_slot_detection_init();
>> +}
>> +
>> static inline int pciehp_get_hp_hw_control_from_firmware(struct pci_dev *dev)
>> {
>> + int retval;
>> u32 flags = (OSC_PCI_EXPRESS_NATIVE_HP_CONTROL |
>> OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
>> - return acpi_get_hp_hw_control_from_firmware(dev, flags);
>> + retval = acpi_get_hp_hw_control_from_firmware(dev, flags);
>> + if (retval)
>> + return retval;
>> + return pciehp_acpi_slot_detection_check(dev);
>> }
>>
>> static inline int pciehp_get_hp_params_from_firmware(struct pci_dev *dev,
>> @@ -235,6 +247,7 @@ static inline int pciehp_get_hp_params_f
>> return 0;
>> }
>> #else
>> +#define pciehp_firmware_init() do {} while (0)
>> #define pciehp_get_hp_hw_control_from_firmware(dev) 0
>> #define pciehp_get_hp_params_from_firmware(dev, hpp) (-ENODEV)
>> #endif /* CONFIG_ACPI */
>> Index: 20081212/drivers/pci/hotplug/pciehp_acpi.c
>> ===================================================================
>> --- /dev/null
>> +++ 20081212/drivers/pci/hotplug/pciehp_acpi.c
>> @@ -0,0 +1,114 @@
>> +/*
>> + * 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 "pciehp.h"
>> +
>> +#define PCIEHP_DETECT_PCIE (0)
>> +#define PCIEHP_DETECT_ACPI (1)
>> +#define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_PCIE
>> +
>> +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\n"
>> + " pcie - Use PCIe based slot detection (default)\n"
>> + " acpi - Use ACPI for slot detection\n");
>> +
>
> I would prefer that we do not add module params at all, and just
> make the driver always autodetect the mode. You have the 'auto'
> code in your 2nd patch, but it would be better to remove the
> params and just always do the autodetect.
>
>> +static int is_ejectable(acpi_handle handle)
>> +{
>> + acpi_status status;
>> + acpi_handle tmp;
>> + unsigned long long removable;
>> + status = acpi_get_handle(handle, "_ADR", &tmp);
>> + if (ACPI_FAILURE(status))
>> + return 0;
>> + status = acpi_get_handle(handle, "_EJ0", &tmp);
>> + if (ACPI_SUCCESS(status))
>> + return 1;
>> + status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
>> + if (ACPI_SUCCESS(status) && removable)
>> + return 1;
>> + return 0;
>> +}
>> +
>> +static acpi_status
>> +check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
>> +{
>> + int *found = (int *)context;
>> + if (is_ejectable(handle)) {
>> + *found = 1;
>> + return AE_CTRL_TERMINATE;
>> + }
>> + return AE_OK;
>> +}
>
> This code is very similar to what we already have in acpiphp.
>
> Is there any way you could figure out how to make both pciehp and
> acpiphp share this code?
>
Yes, we can put those functions in pcihp_acpi.c so that pciehp and
acpiphp share the code. I'll update the patch.
Thanks,
Kenji Kaneshige
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