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authorRudolf Marek <r.marek@assembler.cz>2007-05-27 22:17:43 +0200
committerJean Delvare <khali@hyperion.delvare>2007-05-27 22:17:43 +0200
commit67f363b1f6a31cf5027a97372f64bcced4f05ba6 (patch)
tree7b9af1465c0310793d0049353d7f54199860b94f /drivers/hwmon/coretemp.c
parent7574d7e937f81754dfd82deac24aea5880107e2d (diff)
hwmon/coretemp: Add more safety checks
Add detection of AE18 Errata of Core processor and warns users that the absolute readings might be wrong for Core2 processor. Signed-off-by: Rudolf Marek <r.marek@assembler.cz> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/hwmon/coretemp.c')
-rw-r--r--drivers/hwmon/coretemp.c32
1 files changed, 29 insertions, 3 deletions
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 75e3911810a..0328382df8f 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -176,6 +176,22 @@ static int __devinit coretemp_probe(struct platform_device *pdev)
goto exit_free;
}
+ /* Check if we have problem with errata AE18 of Core processors:
+ Readings might stop update when processor visited too deep sleep,
+ fixed for stepping D0 (6EC).
+ */
+
+ 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) {
+ dev_err(&pdev->dev,
+ "Errata AE18 not fixed, update BIOS or "
+ "microcode of the CPU!\n");
+ goto exit_free;
+ }
+ }
+
/* Some processors have Tjmax 85 following magic should detect it
Intel won't disclose the information without signed NDA, but
individuals cannot sign it. Catch(ed) 22.
@@ -193,6 +209,19 @@ static int __devinit coretemp_probe(struct platform_device *pdev)
}
}
+ /* Intel says that above should not work for desktop Core2 processors,
+ but it seems to work. There is no other way how get the absolute
+ readings. Warn the user about this. First check if are desktop,
+ bit 50 of MSR_IA32_PLATFORM_ID should be 0.
+ */
+
+ rdmsr_safe_on_cpu(data->id, MSR_IA32_PLATFORM_ID, &eax, &edx);
+
+ if ((c->x86_model == 0xf) && (!(edx & 0x00040000))) {
+ dev_warn(&pdev->dev, "Using undocumented features, absolute "
+ "temperature might be wrong!\n");
+ }
+
platform_set_drvdata(pdev, data);
if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
@@ -330,9 +359,6 @@ static int __init coretemp_init(void)
int i, err = -ENODEV;
struct pdev_entry *p, *n;
- printk(KERN_NOTICE DRVNAME ": This driver uses undocumented features "
- "of Core CPU. Temperature might be wrong!\n");
-
/* quick check if we run Intel */
if (cpu_data[0].x86_vendor != X86_VENDOR_INTEL)
goto exit;