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authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2006-12-19 12:58:55 -0800
committerDave Jones <davej@redhat.com>2006-12-22 22:45:41 -0500
commit8edc59d939ad233c24385fb67a62bd39db532901 (patch)
tree68f3f3fabc5310d0d3c0cdae1db1d4aef33ddccd /drivers/cpufreq
parent917325d30ab12f9f23aee5c91dc96dfe81b0c6be (diff)
downloadlinux-8edc59d939ad233c24385fb67a62bd39db532901.tar.gz
[CPUFREQ] Bug fix for acpi-cpufreq and cpufreq_stats oops on frequency change notification
Fixes the oops in cpufreq_stats with acpi_cpufreq driver.  The issue was
that the frequency was reported as 0 in acpi-cpufreq.c.  The bug is due to
different indicies for freq_table and ACPI perf table.

Also adds a check in cpufreq_stats to check for error return from
freq_table_get_index() and avoid using the error return value.

Patch fixes the issue reported at
http://www.ussg.iu.edu/hypermail/linux/kernel/0611.2/0629.html
and also other similar issue here
http://bugme.osdl.org/show_bug.cgi?id=7383 comment 53

Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq_stats.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 6742b1adf2c8..91ad342a6051 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -285,6 +285,7 @@ cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
 	stat = cpufreq_stats_table[freq->cpu];
 	if (!stat)
 		return 0;
+
 	old_index = freq_table_get_index(stat, freq->old);
 	new_index = freq_table_get_index(stat, freq->new);
 
@@ -292,6 +293,9 @@ cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
 	if (old_index == new_index)
 		return 0;
 
+	if (old_index == -1 || new_index == -1)
+		return 0;
+
 	spin_lock(&cpufreq_stats_lock);
 	stat->last_index = new_index;
 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS