From b930fe5e1f5646e071facda70b25b137ebeae5af Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Thu, 26 Apr 2012 14:22:33 -0400
Subject: xen/acpi: Workaround broken BIOSes exporting non-existing C-states.

We did a similar check for the P-states but did not do it for
the C-states. What we want to do is ignore cases where the DSDT
has definition for sixteen CPUs, but the machine only has eight
CPUs and we get:
xen-acpi-processor: (CX): Hypervisor error (-22) for ACPI CPU14

Reported-by: Tobias Geiger <tobias.geiger@vido.info>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/xen/xen-acpi-processor.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'drivers/xen/xen-acpi-processor.c')

diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
index 174b5653cd8..0b48579a9cd 100644
--- a/drivers/xen/xen-acpi-processor.c
+++ b/drivers/xen/xen-acpi-processor.c
@@ -128,7 +128,10 @@ static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
 			pr_debug("     C%d: %s %d uS\n",
 				 cx->type, cx->desc, (u32)cx->latency);
 		}
-	} else
+	} else if (ret != -EINVAL)
+		/* EINVAL means the ACPI ID is incorrect - meaning the ACPI
+		 * table is referencing a non-existing CPU - which can happen
+		 * with broken ACPI tables. */
 		pr_err(DRV_NAME "(CX): Hypervisor error (%d) for ACPI CPU%u\n",
 		       ret, _pr->acpi_id);
 
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