thinkpad_acpi patch for Lenovo P50

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index e305ab5..4f65a22 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -324,6 +324,8 @@ static struct {
    u32 has_adaptive_kbd:1;
 } tp_features;

+static u8 active_fan;
+
 static struct {
    u16 hotkey_mask_ff:1;
    u16 volume_ctrl_forbidden:1;
@@ -7907,6 +7909,14 @@ static bool fan_select_fan2(void)
    return true;
 }

+static void fan_select_fan(void)
+{
+  if(active_fan == 1)
+    fan_select_fan1();
+  else
+    fan_select_fan2();
+}
+
 /*
  * Call with fan_mutex held
  */
@@ -8059,6 +8069,7 @@ static int fan_set_level(int level)
        else if (level & TP_EC_FAN_AUTO)
            level |= 4; /* safety min speed 4 */

+                fan_select_fan();
        if (!acpi_ec_write(fan_status_offset, level))
            return -EIO;
        else
@@ -8403,6 +8414,54 @@ static ssize_t fan_pwm1_store(struct device *dev,

 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, fan_pwm1_show, fan_pwm1_store);

+static ssize_t fan_pwm2_enable_show(struct device *dev,
+                   struct device_attribute *attr,
+                   char *buf)
+{
+  ssize_t result;
+  active_fan = 2;
+  result = fan_pwm1_enable_show(dev,attr,buf);
+  active_fan = 1;
+  return result;
+}
+
+static ssize_t fan_pwm2_enable_store(struct device *dev,
+                    struct device_attribute *attr,
+                    const char *buf, size_t count)
+{
+  ssize_t result;
+  active_fan = 2;
+  result = fan_pwm1_enable_store(dev,attr,buf,count);
+  active_fan = 1;
+  return result;
+}
+
+static ssize_t fan_pwm2_show(struct device *dev,
+                struct device_attribute *attr,
+                char *buf)
+{
+  ssize_t result;
+  active_fan = 2;
+  result = fan_pwm1_show(dev,attr,buf);
+  active_fan = 1;
+  return result;
+}
+
+static ssize_t fan_pwm2_store(struct device *dev,
+                 struct device_attribute *attr,
+                 const char *buf, size_t count)
+{
+  ssize_t result;
+  active_fan = 2;
+  result = fan_pwm1_store(dev,attr,buf,count);
+  active_fan = 1;
+  return result;
+}
+
+static DEVICE_ATTR(pwm2_enable, S_IWUSR | S_IRUGO,
+          fan_pwm2_enable_show, fan_pwm2_enable_store);
+static DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, fan_pwm2_show, fan_pwm2_store);
+
 /* sysfs fan fan1_input ------------------------------------------------ */
 static ssize_t fan_fan1_input_show(struct device *dev,
               struct device_attribute *attr,
@@ -8470,6 +8529,7 @@ static DRIVER_ATTR(fan_watchdog, S_IWUSR | S_IRUGO,
 static struct attribute *fan_attributes[] = {
    &dev_attr_pwm1_enable.attr, &dev_attr_pwm1.attr,
    &dev_attr_fan1_input.attr,
+   &dev_attr_pwm2_enable.attr, &dev_attr_pwm2.attr,
    NULL, /* for fan2_input */
    NULL
 };
@@ -8518,7 +8578,7 @@ static int __init fan_init(struct ibm_init_struct *iibm)
    fan_control_commands = 0;
    fan_watchdog_maxinterval = 0;
    tp_features.fan_ctrl_status_undef = 0;
-   tp_features.second_fan = 0;
+   tp_features.second_fan = 1;
    fan_control_desired_level = 7;

    if (tpacpi_is_ibm()) {