hwmon: (k8temp) Fix temperature reporting for (most) K8 RevG CPUs

Current Temperature for K8 RevG desktop CPUs is a "normalized value"
which can be below ambient temperature.

As a consequence lots of RevG systems report temperatures like:

$ sensors
k8temp-pci-00c3
Adapter: PCI adapter
Core0 Temp:    +17 C
Core0 Temp:     +3 C
Core1 Temp:    +21 C
Core1 Temp:     +5 C

being quite below ambient temperature.
There are even reports of negative temperature values.

This patch corrects the temperature reporting of k8temp for
RevG desktop CPUs.

Cc: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/hwmon/k8temp.c b/drivers/hwmon/k8temp.c
index a6381bc9189c..1fe995111841 100644
--- a/drivers/hwmon/k8temp.c
+++ b/drivers/hwmon/k8temp.c
@@ -49,6 +49,7 @@ struct k8temp_data {
         u8 sensorsp;            /* sensor presence bits - SEL_CORE & SEL_PLACE */
         u32 temp[2][2];         /* core, place */
         u8 swap_core_select;    /* meaning of SEL_CORE is inverted */
+        u32 temp_offset;
 };
 
 static struct k8temp_data *k8temp_update_device(struct device *dev)
@@ -116,13 +117,15 @@ static ssize_t show_temp(struct device *dev,
             to_sensor_dev_attr_2(devattr);
         int core = attr->nr;
         int place = attr->index;
+        int temp;
         struct k8temp_data *data = k8temp_update_device(dev);
 
         if (data->swap_core_select)
                 core = core ? 0 : 1;
 
-        return sprintf(buf, "%d\n",
-                       TEMP_FROM_REG(data->temp[core][place]));
+        temp = TEMP_FROM_REG(data->temp[core][place]) + data->temp_offset;
+
+        return sprintf(buf, "%d\n", temp);
 }
 
 /* core, place */
@@ -176,6 +179,16 @@ static int __devinit k8temp_probe(struct pci_dev *pdev,
                                  "wrong - check erratum #141\n");
                 }
 
+                if ((model >= 0x69) &&
+                    !(model == 0xc1 || model == 0x6c || model == 0x7c)) {
+                        /*
+                         * RevG desktop CPUs (i.e. no socket S1G1 parts)
+                         * need additional offset, otherwise reported
+                         * temperature is below ambient temperature
+                         */
+                        data->temp_offset = 21000;
+                }
+
                 break;
         }