Re: [PATCH] fix(Fix _STA checking in acpi_bus_add)

[Len Brown <len.brown-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

The ACPI spec gurus say that as of 2.0c,
_STA.functional is meaningless unless _STA.present.

However, they also say that the (_STA.functional && !_STA.present)
implementation was intentional -- apparently to trick some OSPM into
using a resource for initialization only, but to not load
a driver.

So...

I'm advocating that the spec be clarified to explicitly
allow or disallow this idiom.

In the mean-time, Bjorn's patch is now present in the acpi-test tree.

-Len

On Wed, 2004-05-12 at 00:40, Len Brown wrote:
> As this is needed by more than just Big Sur,
> I'm okay with applying Bjorn's workaround to acpi-test
> (and thus -mm) while we wait for definitive word
> from the spec writers.  We can always back it out
> or make it system specific later.  I have no fear
> that we'll break docking stations, because at this
> point we have no docking station support...
> 
> thanks,
> -Len
> 
> On Thu, 2004-04-29 at 04:18, Simon Derr wrote:
> > On Wed, 28 Apr 2004, Bjorn Helgaas wrote:
> > 
> > > Is your box based on Intel chipsets and/or firmware?  You might be
> > Indeed.
> > 
> > > suffering from the problem I described here:
> > >
> > >     https://sourceforge.net/mailarchive/message.php?msg_id=6923358
> > >
> > > Intel firmware seems to describe the PCI root bridge where chipset
> > > configuration space lives with _STA==0x8.  The spec says this means
> > > "functional, but not present".  The current Linux code ignores things
> > > that are "not present".
> > 
> > I tried your patch and it works perfectly. Thank you.
> > This chipset/firmware is probably very common in the ia64 world so I think
> > it might be a good idea to include your patch in the stock Linux kernel.
> > 
> > 	Simon.
> > 
> > This is just your patch with updated line offsets, applies cleanly to
> > Linux 2.6.5:
> > 
> > --- linux-2.6.5-vanilla/drivers/acpi/bus.c	Sun Apr  4 05:37:24 2004
> > +++ linux-2.6.5/drivers/acpi/bus.c	Thu Apr 29 09:43:14 2004
> > @@ -112,6 +112,14 @@
> >  	else
> >  		STRUCT_TO_INT(device->status) = 0x0F;
> > 
> > +	if (device->status.functional && !device->status.present) {
> > +		printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
> > +			"functional but not present; setting present\n",
> > +			device->pnp.bus_id,
> > +			(u32) STRUCT_TO_INT(device->status));
> > +		device->status.present = 1;
> > +	}
> > +
> >  	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
> >  		device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status)));
> > 
> > 
> > 
> > -------------------------------------------------------
> > This SF.Net email is sponsored by: Oracle 10g
> > Get certified on the hottest thing ever to hit the market... Oracle 10g. 
> > Take an Oracle 10g class now, and we'll give you the exam FREE.
> > http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click
> > _______________________________________________
> > Acpi-devel mailing list
> > Acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
> > https://lists.sourceforge.net/lists/listinfo/acpi-devel
> 
> 
> 
> -------------------------------------------------------
> This SF.Net email is sponsored by Sleepycat Software
> Learn developer strategies Cisco, Motorola, Ericsson & Lucent use to deliver
> higher performing products faster, at low TCO.
> http://www.sleepycat.com/telcomwpreg.php?From=osdnemail3
> _______________________________________________
> Acpi-devel mailing list
> Acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
> https://lists.sourceforge.net/lists/listinfo/acpi-devel



-------------------------------------------------------
This SF.Net email is sponsored by Sleepycat Software
Learn developer strategies Cisco, Motorola, Ericsson & Lucent use to deliver
higher performing products faster, at low TCO.
http://www.sleepycat.com/telcomwpreg.php?From=osdnemail3