linux-kernel - Re: [Bug report] Warning when hot-add an ACPI0004 device.

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Date:	Thu, 26 Sep 2013 10:33:20 +0800
From:	Gu Zheng <guz.fnst@...fujitsu.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
CC:	Toshi Kani <toshi.kani@...com>,
	Tang Chen <tangchen@...fujitsu.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	Yasuaki Ishimatsu <isimatu.yasuaki@...fujitsu.com>
Subject: Re: [Bug report] Warning when hot-add an ACPI0004 device.

Hi Rafael,

On 09/25/2013 10:36 PM, Rafael J. Wysocki wrote:

> On Wednesday, September 25, 2013 06:31:09 PM Gu Zheng wrote:
>> Hi Toshi,
>>
>> On 09/12/2013 11:11 PM, Toshi Kani wrote:
>>
>>> On Thu, 2013-09-12 at 13:00 +0800, Tang Chen wrote:
>>>> Hi Rafael, Toshi,
>>>>
>>>> When we hot-add an ACPI0004 device, we got the following warning:
>>>>
>>>> 	acpi ACPI0004:01: Attempt to re-insert
<...>
>>>>
>>>>
>>>> I'm now investigating this problem. If you have any idea about why this
>>>> happens, please let me know.
>>>
>>> With the above change, container devices use the common notify handler,
>>> which logs the warning message in question when it receives device check
>>> twice on a same device.  Before the change, the container-specific
>>> notify handler did not log this message in the same case (but considered
>>> it as an eject request).
>>>
>>> So, I suspect that you are getting device check twice regardless of the
>>> kernel change.  Can you check KERN_DEBUG messages to see if that is the
>>> case?  The notify handler logs all events with KERN_DEBUG.
>>
>> Follow your suggestion, we confirm that it really received ACPI_NOTIFY_
>> DEVICE_CHECK event*twice*, but the original ACPI container driver only
>> received once, does the common device hotplug code introduce another device
>> check? any idea?
> 
> Well, we couldn't possibly make the BIOS generate the event twice unless
> there's an _OST response missing somewhere or similar.
> 
> In any case the second event should be harmless.

Yes, though it's harmless, but this message is not very friendly. 

> 
>> Container uses common device hotplug code:
>> [  142.937724] IPv6: ADDRCONF(NETDEV_CHANGE): eth8: link becomes ready
>> [  674.975575] ACPI: \_SB_.LSB1: ACPI_NOTIFY_DEVICE_CHECK event          <<<<
>> [  674.991604] ACPI: \_SB_.LSB1: ACPI_NOTIFY_DEVICE_CHECK event		 <<<<	
> 
> Where exactly did you put that printk()?

It's the acpi_handle_debug in acpi_hotplug_notify_cb():
 410         case ACPI_NOTIFY_DEVICE_CHECK:                                          
 411                 acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");  
 412                 callback = acpi_scan_device_check;                              
 413                 break;  

> 
>> [  675.613990] ACPI: PCI Root Bridge [UNC2] (domain 0000 [bus fd])
>> [  675.684970] acpi PNP0A03:01: ACPI _OSC support notification failed, disabling PCIe ASPM
>> [  675.780957] acpi PNP0A03:01: Unable to request _OSC control (_OSC support mask: 0x08)
>> [  675.874806] ACPI _OSC control for PCIe not granted, disabling ASPM
>> [  675.949005] pci_bus 0000:fd: Allocating resources
>> [  675.960145] ACPI: PCI Root Bridge [UNC3] (domain 0000 [bus fc])
>> [  676.031176] acpi PNP0A03:02: ACPI _OSC support notification failed, disabling PCIe ASPM
>> [  676.127129] acpi PNP0A03:02: Unable to request _OSC control (_OSC support mask: 0x08)
>> [  676.220943] ACPI _OSC control for PCIe not granted, disabling ASPM
>> [  676.295019] pci_bus 0000:fc: Allocating resources
>>
>> Original ACPI container driver:
>> [ 1526.122933] Container driver received ACPI_NOTIFY_DEVICE_CHECK event <<<<
> 
> And that?

It seems that the original ACPI container driver can avoid the second event.

The debug printk is added in original container_notify_cb():
 96         case ACPI_NOTIFY_DEVICE_CHECK:
 97                 printk("Container driver received %s event\n",
 98                        (type == ACPI_NOTIFY_BUS_CHECK) ?
 99                        "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
100 
101                 present = is_device_present(handle);
102                 status = acpi_bus_get_device(handle, &device);
103                 if (device)
104                         printk("=======attemp to reinsert!\n");
105                 if (!present) {

Best regards,
Gu

> 
>> [ 1526.800646] ACPI: PCI Root Bridge [UNC2] (domain 0000 [bus fd])
>> [ 1526.871682] acpi PNP0A03:01: ACPI _OSC support notification failed, disabling PCIe ASPM
>> [ 1526.967878] acpi PNP0A03:01: Unable to request _OSC control (_OSC support mask: 0x08)
>> [ 1527.061891] ACPI _OSC control for PCIe not granted, disabling ASPM
>> [ 1527.136036] pci_bus 0000:fd: Allocating resources
>> [ 1527.150747] ACPI: PCI Root Bridge [UNC3] (domain 0000 [bus fc])
>> [ 1527.221821] acpi PNP0A03:02: ACPI _OSC support notification failed, disabling PCIe ASPM
>> [ 1527.317738] acpi PNP0A03:02: Unable to request _OSC control (_OSC support mask: 0x08)
>> [ 1527.411795] ACPI _OSC control for PCIe not granted, disabling ASPM
>> [ 1527.485917] pci_bus 0000:fc: Allocating resources
> 
> Thanks,
> Rafael
> 
> 


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