Re: [PATCH] ACPI: power: Use KERN_DEBUG when no power resources are found

From: Rafael J. Wysocki
Date: Thu Sep 13 2012 - 17:11:11 EST


On Thursday, September 13, 2012, Borislav Petkov wrote:
> On Wed, Aug 29, 2012 at 10:01:36AM +0800, Aaron Lu wrote:
> > On Fri, Aug 24, 2012 at 03:36:21PM -0700, Joe Perches wrote:
> > > On Thu, 2012-08-23 at 15:26 +0200, Borislav Petkov wrote:
> > > > On Fri, Aug 10, 2012 at 10:05:53AM +0800, Aaron Lu wrote:
> > > > > commit a606dac368eed5696fb38e16b1394f1d049c09e9 adds support to link
> > > > > devices which have _PRx, if a device does not have _PRx, a warning
> > > > > message will be printed.
> > > > >
> > > > > This commit is for ZPODD on Intel's platform, on AMD's platform, there
> > > > > is no _PRx to support ZPODD, we use _PSx.
> > > > >
> > > > > So instead of printing a useless warning message on AMD's platform,
> > > > > changing the print level to DEBUG to suppress this message.
> > > []
> > > > > diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
> > > []
> > > > > @@ -460,7 +460,7 @@ int acpi_power_resource_register_device(struct device *dev, acpi_handle handle)
> > > > > return ret;
> > > > >
> > > > > no_power_resource:
> > > > > - printk(KERN_WARNING PREFIX "Invalid Power Resource to register!");
> > > > > + printk(KERN_DEBUG PREFIX "Invalid Power Resource to register!");
> > >
> > > Perhaps add something like:
> > > if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
> > > printk(etc...)
> > > instead?
> >
> > Sorry for not describing this problem clear, this would also occur on
> > Intel platforms as long as that device we are calling this register
> > function on does not have any power resource attached to it.
> >
> > So the problem is actually, does the acpi_power_resource_register_device
> > function expect such input devices that they do not have any power
> > resource attached? If yes, then it shouldn't complain with a warning
> > message; if no, then we should probably check these conditions before
> > making such a call.
> >
> > Looking at the function itself, I think it expects such devices so a
> > warning message here is not appropriate.
>
> This is still present in -rc5.
>
> Linus, this message obviously warns for no good reason. Can you please
> pick up the patch at http://marc.info/?l=linux-kernel&m=134456468110431
> since ACPI people don't seem to react here.

I'll take it. There are two more ACPI PM patches that would be good to have
in v3.6 IMO.

Thanks,
Rafael
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