Changeset 1168

Timestamp:

09/01/01 16:33:41 (12 years ago)

Author:

mds

Message:

fix unreliable initialization of limit registers by

adding a rather large delay after resetting the device
via register 0x40. There is obviously a state machine
in the chip that takes a while to run after you reset it.
Figured out the delay time by trial and error.

Location:

lm-sensors/trunk

Files:

• CHANGES (modified) (1 diff)
• kernel/chips/via686a.c (modified) (2 diffs)

lm-sensors/trunk/CHANGES

@@ -17 +17 @@
 
 -----------------------------------------------------------------------------
+
+2.6.2 (2001????)
+  Module via686a: Make limit initializations reliable
 
 2.6.1 (20010830)

lm-sensors/trunk/kernel/chips/via686a.c

@@ -41 +41 @@
 #include <asm/io.h>
 #include <linux/types.h>
+#include <linux/delay.h>
 #include <linux/i2c.h>
 #include "version.h"
@@ -681 +682 @@
         via686a_write_value(client, VIA686A_REG_CONFIG, 0x80);
 
+        /* Have to wait for reset to complete or else the following
+           initializations won't work reliably. The delay was arrived at
+           empirically, the datasheet doesn't tell you.
+           Waiting for the reset bit to clear doesn't work, it
+           clears in about 2-4 udelays and that isn't nearly enough. */
+        udelay(50);
+
         via686a_write_value(client, VIA686A_REG_IN_MIN(0),
                             IN_TO_REG(VIA686A_INIT_IN_MIN_0, 0));