[PATCH] Fix powernow oops on dual-core athlon

Date: Thu, 28 Jul 2005 16:38:21 +0000 (-0700)
Subject: powernow-k8 requires that a data structure for
X-Git-Tag: v2.6.13-rc4
X-Git-Url: http://www.kernel.org/git/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=03938c3f1062b0f279a0ef937a471d4db83702ed

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@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Chris Wright <chrisw@osdl.org>

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(struct cpufreq_policy *pol)
 {
 	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(struct cpufreq_policy *pol)
 	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;