Fix PECI/AMDTSI selection

We can not use register 0x98 since it is typically not programmed
on systems selecting PECI. Try register 0x0a (Interface Selection)
which should be a better fit anyway.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/it87.c b/it87.c
index 8a51027b38cfc0b1280f742f855f081108285364..7c1e7e41dcbaa882ec13600dda674b6a790cd569 100644 (file)
--- a/it87.c
+++ b/it87.c
@@ -258,6 +258,10 @@ static bool fix_pwm_polarity;
  * Super-I/O configuration space.
  */
 #define IT87_REG_VID           0x0a
+
+/* Interface Selection register on other chips */
+#define IT87_REG_IFSEL         0x0a
+
 /*
  * The IT8705F and IT8712F earlier than revision 0x08 use register 0x0b
  * for fan divisors. Later IT8712F revisions must use 16-bit tachometer
@@ -1465,11 +1469,12 @@ static int get_temp_type(struct it87_data *data, int index)
        if (type)
                return type;
 
-       /* Dectect PECI vs. AMDTSI if possible */
+       /* Dectect PECI vs. AMDTSI */
        ttype = 6;
-       if ((has_temp_peci(data, index)) && data->type != it8721) {
-               extra = data->read(data, 0x98); /* PCH/AMDTSI host status */
-               if (extra & BIT(6))
+       if ((has_temp_peci(data, index)) || data->type == it8721 ||
+           data->type == it8720) {
+               extra = data->read(data, IT87_REG_IFSEL);
+               if ((extra & 0x70) == 0x40)
                        ttype = 5;
        }