linux-kernel - Re: [RFC PATCH v5 8/8] PCI/PCIe: only claim PME from firmware when CONFIG_PCIE

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Date:	Tue, 22 Jan 2013 01:06:54 +0800
From:	Jiang Liu <liuj97@...il.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
CC:	Bjorn Helgaas <bhelgaas@...gle.com>,
	Jiang Liu <jiang.liu@...wei.com>,
	Yinghai Lu <yinghai@...nel.org>,
	Kenji Kaneshige <kaneshige.kenji@...fujitsu.com>,
	Yijing Wang <wangyijing@...wei.com>,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
	Toshi Kani <toshi.kani@...com>,
	Myron Stowe <myron.stowe@...hat.com>
Subject: Re: [RFC PATCH v5 8/8] PCI/PCIe: only claim PME from firmware when
 CONFIG_PCIE_PME is enabled

On 01/21/2013 07:43 AM, Rafael J. Wysocki wrote:
> On Saturday, January 19, 2013 12:07:46 AM Jiang Liu wrote:
>> If CONFIG_PCIE_PME is not defined, system should avoid claiming PME from
>> firmware so firmware could still manage PME events for those devices.
>> Also don't create PCIe port device for PME service if CONFIG_PCIE_PME
>> is not defined.
> 
> No, this isn't correct.
> 
> We know from experience that it is in fact necessary to request control of
> either all PCIe native features or none of them.  Anything else leads to
> very "interesting" failure modes on some systems.
> 
> I think we should just remove CONFIG_PCIE_PME instead.
Hi Rafael,
	Thanks for reminder, don't know these tricky things about BIOS:)
Seems we can't easily remove CONFIG_PCIE_PME currently, so I will just
drop this patch.
Regards!
Gerry

> 
> Thanks,
> Rafael
> 
> 
>> Signed-off-by: Jiang Liu <jiang.liu@...wei.com>
>> ---
>>  drivers/acpi/pci_root.c         |    5 +++--
>>  drivers/pci/pcie/portdrv_core.c |    4 +++-
>>  2 files changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
>> index c37eedb..7f7e464 100644
>> --- a/drivers/acpi/pci_root.c
>> +++ b/drivers/acpi/pci_root.c
>> @@ -550,8 +550,9 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
>>  
>>  	if (!pcie_ports_disabled
>>  	    && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
>> -		flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
>> -			| OSC_PCI_EXPRESS_PME_CONTROL;
>> +		flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL;
>> +		if (IS_ENABLED(CONFIG_PCIE_PME))
>> +			flags |= OSC_PCI_EXPRESS_PME_CONTROL;
>>  		if (!pcie_native_hotplug_disabled)
>>  			flags |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
>>  
>> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
>> index e7e1679..7e6546f 100644
>> --- a/drivers/pci/pcie/portdrv_core.c
>> +++ b/drivers/pci/pcie/portdrv_core.c
>> @@ -263,7 +263,9 @@ static int get_port_device_capability(struct pci_dev *dev)
>>  
>>  	err = pcie_port_platform_notify(dev, &cap_mask);
>>  	if (!pcie_ports_auto) {
>> -		cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_VC;
>> +		cap_mask = PCIE_PORT_SERVICE_VC;
>> +		if (IS_ENABLED(CONFIG_PCIE_PME))
>> +			cap_mask |= PCIE_PORT_SERVICE_PME;
>>  		if (!pcie_native_hotplug_disabled)
>>  			cap_mask |= PCIE_PORT_SERVICE_HP;
>>  		if (pci_aer_available())
>>

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