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

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.

> The call chain is:
> device_probe_child -> device_set_devclass -> devclass_add_device ->
> devclass_alloc_unit.

That is, the unit for the wildcard devices should still be -1 here and should not
even get to this message.

I wonder if this is related to the recent changes to set the unit number for CPUs?

-- 
John Baldwin