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>

diff --git a/drivers/hwmon/k8temp.c b/drivers/hwmon/k8temp.c
index a6381bc..1fe9951 100644 (file)
--- 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;
        }