Re: 2.6.35-rc3 regression: IBM Maia system is unbootable [ACPIrelated?]
From: James Bottomley
Date: Tue Jun 29 2010 - 12:49:26 EST
On Mon, 2010-06-28 at 23:49 -0400, Len Brown wrote:
> From: Len Brown <len.brown@xxxxxxxxx>
> Subject: [PATCH] ACPI: handle systems which asynchoronously enable ACPI mode
> Folklore suggested that such systems existed
> in the pre-history of ACPI.
> However, we removed the SCI_EN polling loop from
> acpi_hw_set_mode() in b430acbd7c4b919886fa7fd92eeb7a695f1940d3
> because it delayed resume by 3 seconds on boxes
> that refused to set SCI_EN.
> Matthew removed the call to acpi_enable() from
> the suspend resume path.
> James found a modern system that still needs to be polled
> upon boot.
> So here we restore the workaround, except that we
> put it in acpi_enable() rather than the low level
> Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
> James, What does the IBM system see with this patch?
The output is this:
[ 0.084088] ACPI: Core revision 20100428
[ 0.119451] ACPI Warning: Platform took > 100 usec to enter ACPI mode (20100428/evxfevnt-106)
[ 0.128231] Setting APIC routing to physical flat
So it's very fast ... actually it's behaving like there's some caching
issue and it needs two reads to return the correct value
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/