[13/13] Fix powernow oops on dual-core athlon

From: Chris Wright
Date: Wed Aug 03 2005 - 02:14:20 EST


-stable review patch. If anyone has any objections, please let us know.

------------------

powernow-k8 requires that a data structure for
each core be created in the _cpu_init function
call. The cpufreq infrastructure doesn't call
_cpu_init for the second core in each processor.
Some systems crashed when _get was called with
an odd-numbered core because it tried to
dereference a NULL pointer since the data
structure had not been created.

The attached patch solves the problem by
initializing data structures for all shared
cores in the _cpu_init function. It should
apply to 2.6.12-rc6 and has been tested by
AMD and Sun.

Signed-off-by: Mark Langsdorf <mark.langsdorf@xxxxxxx>
Signed-off-by: Dave Jones <davej@xxxxxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxx>
---

--- a/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
@@ -44,7 +44,7 @@

#define PFX "powernow-k8: "
#define BFX PFX "BIOS error: "
-#define VERSION "version 1.40.2"
+#define VERSION "version 1.40.4"
#include "powernow-k8.h"

/* serialize freq changes */
@@ -978,7 +978,7 @@ static int __init powernowk8_cpu_init(st
{
struct powernow_k8_data *data;
cpumask_t oldmask = CPU_MASK_ALL;
- int rc;
+ int rc, i;

if (!check_supported_cpu(pol->cpu))
return -ENODEV;
@@ -1064,7 +1064,9 @@ static int __init powernowk8_cpu_init(st
printk("cpu_init done, current fid 0x%x, vid 0x%x\n",
data->currfid, data->currvid);

- powernow_data[pol->cpu] = data;
+ for_each_cpu_mask(i, cpu_core_map[pol->cpu]) {
+ powernow_data[i] = data;
+ }

return 0;

-
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