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authorJan Beulich <JBeulich@novell.com>2010-10-08 04:59:38 -0400
committerGuenter Roeck <guenter.roeck@ericsson.com>2010-10-25 14:11:21 -0700
commit3247800676c4a04352cde72b9935b57ffc72ce15 (patch)
tree5918c72fe4fbdf6f224f1e62661445870939e894 /drivers/hwmon
parent17c10d61c750619324ee2a46c5a9e03a435fe212 (diff)
hwmon: (coretemp) fix reading of microcode revision (v2)
According to the documentation, simply reading the respective MSR isn't sufficient: It should be written with zeros, cpuid(1) be executed, and then read (see arch/x86/kernel/cpu/intel.c for an example). v2: Fail probe when microcode revision cannot be determined, but is needed to check for proper operation. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Chen Gong <gong.chen@linux.intel.com> Cc: Jean Delvare <khali@linux-fr.org> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/coretemp.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 467488c278e..42de98d73ff 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -289,6 +289,15 @@ static int __devinit get_tjmax(struct cpuinfo_x86 *c, u32 id,
}
}
+static void __devinit get_ucode_rev_on_cpu(void *edx)
+{
+ u32 eax;
+
+ wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+ sync_core();
+ rdmsr(MSR_IA32_UCODE_REV, eax, *(u32 *)edx);
+}
+
static int __devinit coretemp_probe(struct platform_device *pdev)
{
struct coretemp_data *data;
@@ -324,8 +333,15 @@ static int __devinit coretemp_probe(struct platform_device *pdev)
if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
/* check for microcode update */
- rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
- if (edx < 0x39) {
+ err = smp_call_function_single(data->id, get_ucode_rev_on_cpu,
+ &edx, 1);
+ if (err) {
+ dev_err(&pdev->dev,
+ "Cannot determine microcode revision of "
+ "CPU#%u (%d)!\n", data->id, err);
+ err = -ENODEV;
+ goto exit_free;
+ } else if (edx < 0x39) {
err = -ENODEV;
dev_err(&pdev->dev,
"Errata AE18 not fixed, update BIOS or "