[lkml]   [2011]   [May]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[56/71] x86, AMD: Fix ARAT feature setting again
2.6.38-stable review patch.  If anyone has any objections, please let us know.


From: Borislav Petkov <>

commit 14fb57dccb6e1defe9f89a66f548fcb24c374c1d upstream.

Trying to enable the local APIC timer on early K8 revisions
uncovers a number of other issues with it, in conjunction with
the C1E enter path on AMD. Fixing those causes much more churn
and troubles than the benefit of using that timer brings so
don't enable it on K8 at all, falling back to the original
functionality the kernel had wrt to that.

Reported-and-bisected-by: Nick Bowler <>
Cc: Boris Ostrovsky <>
Cc: Andreas Herrmann <>
Cc: Greg Kroah-Hartman <>
Cc: Hans Rosenfeld <>
Cc: Nick Bowler <>
Cc: Joerg-Volker-Peetz <>
Signed-off-by: Borislav Petkov <>
Signed-off-by: Ingo Molnar <>
Signed-off-by: Greg Kroah-Hartman <>

arch/x86/kernel/cpu/amd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -596,7 +596,7 @@ static void __cpuinit init_amd(struct cp

/* As a rule processors have APIC timer running in deep C states */
- if (c->x86 >= 0xf && !cpu_has_amd_erratum(amd_erratum_400))
+ if (c->x86 > 0xf && !cpu_has_amd_erratum(amd_erratum_400))
set_cpu_cap(c, X86_FEATURE_ARAT);


 \ /
  Last update: 2011-05-19 20:15    [W:0.221 / U:9.556 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site