Re: ACPI 'driver bug: Unable to set devclass'

on 15/05/2012 17:34 John Baldwin said the following:
> On Monday, May 14, 2012 12:41:37 pm Andriy Gapon wrote:
>> on 14/05/2012 01:43 Bruce Cran said the following:
>>> On 13/05/2012 21:06, Andriy Gapon wrote:
>>>> Can you produce an equivalent snippet with verbose logging enabled? I have a
>>>> suspicion that these messages are a byproduct from r231161. 
>>>
>>> acpi0: reservation of fee00000, 1000 (3) failed
>>> acpi0: reservation of 0, a0000 (3) failed
>>> acpi0: reservation of 100000, bbf00000 (3) failed
>>> acpi_sysresource: acpi_sysresource0 already exists; skipping it
>>> driver bug: Unable to set devclass (class: acpi_sysresource devname: (unknown))
>>> acpi_timer: acpi_timer0 already exists; skipping it
>>> driver bug: Unable to set devclass (class: acpi_timer devname: (unknown))
>>> cpu0: <ACPI CPU> on acpi0
>>> ACPI Warning: Incorrect checksum in table [OEMB] - 0x45, should be 0x44
>>> (20120420/tbutils-293)
>>> ACPI: SSDT 0xbb7900f0 01340 (v01 DpgPmm  P001Ist 00000011 INTL 20051117)
>>> ACPI: Dynamic OEM Table Load:
>>> ACPI: SSDT 0 01340 (v01 DpgPmm  P001Ist 00000011 INTL 20051117)
>>> ACPI: SSDT 0xbb791430 004F4 (v01  PmRef  P001Cst 00003001 INTL 20051117)
>>> ACPI: Dynamic OEM Table Load:
>>> ACPI: SSDT 0 004F4 (v01  PmRef  P001Cst 00003001 INTL 20051117)
>>> acpi_sysresource: acpi_sysresource2 already exists; skipping it
>>> driver bug: Unable to set devclass (class: acpi_sysresource devname: (unknown))
>>> cpu2: <ACPI CPU> on acpi0
>>> acpi_sysresource: acpi_sysresource1 already exists; skipping it
>>> driver bug: Unable to set devclass (class: acpi_sysresource devname: (unknown))
>>> cpu1: <ACPI CPU> on acpi0
>>> acpi_sysresource: acpi_sysresource3 already exists; skipping it
>>> driver bug: Unable to set devclass (class: acpi_sysresource devname: (unknown))
>>>
>>
>> I think that the following is what happens here in the acpi_timer case.
>> Previously one acpi_timer device_t was added with an order of zero and a fixed
>> unit number of zero in acpi_timer_identify().  Then, another acpi_timer device_t
>> could be added when walking the ACPI device tree, that device would always have a
>> later order and a wildcard unit number (-1).
>> Now both the "hardwired" device and "auto-probed" device are added with the same
>> order of 2 and it also so happens that the hardwired device is after the
>> auto-probed in the device list.  So first the auto-probed device just takes the
>> unit number of zero because it is free and then the hardwired device fails to
>> claim the same unit number.
> 
> Eh.  This should not be true.  The unit 0 is reserved when device_add_child()
> is called in the acpi_timer identify routine.  The wildcard device will not be
> assigned a unit number until device_probe_child time.

Not sure what you disagree with...
First, the wildcard device is added to the child list during the walk.
Then, the unit 0 device is added to the list when acpi_timer identify is executed.
Then, the wildcard device is probed and gets unit number of zero.
Then, the fixed device is being probed and the unit number conflict arises.

Am I misunderstanding something?

-- 
Andriy Gapon