ChangeSet 1.2329.2.7, 2005/01/14 14:43:30-08:00, [EMAIL PROTECTED]

[PATCH] I2C: fix it87 sensor driver stops CPU fan

> 2* I would then add a check to the it87 driver, which completely disables
> the fan speed control interface if the initial configuration looks weird
> (all fans supposedly stopped and polarity set to "active low"). This
> should protect users of the driver who have a faulty BIOS.
>
> When a bogus configuration is detected, we would of course complain in
> the logs and invite the user to complain to his/her motherboard maker
> too.

Here is it87.c_2.6.10-jm4-detect_broken_bios_20050112.diff implementing
this. It goes on top of the previous patch.

- detects broken bioses, disables the pwm for them and prints a message
- fixes an unrelated minor bug in set_fan_div()

Signed-off-by: Jean Delvare <[EMAIL PROTECTED]>
Signed-off-by: Jonas Munsin <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>


 drivers/i2c/chips/it87.c |   29 ++++++++++++++++++++++-------
 1 files changed, 22 insertions(+), 7 deletions(-)


diff -Nru a/drivers/i2c/chips/it87.c b/drivers/i2c/chips/it87.c
--- a/drivers/i2c/chips/it87.c  2005-01-17 13:20:25 -08:00
+++ b/drivers/i2c/chips/it87.c  2005-01-17 13:20:25 -08:00
@@ -500,7 +500,7 @@
                else
                        data->fan_div[nr] = 3;
        }
-       val = old & 0x100;
+       val = old & 0x80;
        val |= (data->fan_div[0] & 0x07);
        val |= (data->fan_div[1] & 0x07) << 3;
        if (data->fan_div[2] == 3)
@@ -703,6 +703,8 @@
        int err = 0;
        const char *name = "";
        int is_isa = i2c_is_isa_adapter(adapter);
+       int enable_pwm_interface;
+       int tmp;
 
        if (!is_isa && 
            !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
@@ -812,6 +814,17 @@
        /* Initialize the IT87 chip */
        it87_init_client(new_client, data);
 
+       /* Some BIOSes fail to correctly configure the IT87 fans. All fans off
+        * and polarity set to active low is sign that this is the case so we
+        * disable pwm control to protect the user. */
+       enable_pwm_interface = 1;
+       tmp = it87_read_value(new_client, IT87_REG_FAN_CTL);
+       if ((tmp & 0x87) == 0) {
+               enable_pwm_interface = 0;
+               dev_info(&new_client->dev,
+                       "detected broken BIOS defaults, disabling pwm 
interface");
+       }
+
        /* Register sysfs hooks */
        device_create_file(&new_client->dev, &dev_attr_in0_input);
        device_create_file(&new_client->dev, &dev_attr_in1_input);
@@ -860,12 +873,14 @@
        device_create_file(&new_client->dev, &dev_attr_fan2_div);
        device_create_file(&new_client->dev, &dev_attr_fan3_div);
        device_create_file(&new_client->dev, &dev_attr_alarms);
-       device_create_file(&new_client->dev, &dev_attr_pwm1_enable);
-       device_create_file(&new_client->dev, &dev_attr_pwm2_enable);
-       device_create_file(&new_client->dev, &dev_attr_pwm3_enable);
-       device_create_file(&new_client->dev, &dev_attr_pwm1);
-       device_create_file(&new_client->dev, &dev_attr_pwm2);
-       device_create_file(&new_client->dev, &dev_attr_pwm3);
+       if (enable_pwm_interface) {
+               device_create_file(&new_client->dev, &dev_attr_pwm1_enable);
+               device_create_file(&new_client->dev, &dev_attr_pwm2_enable);
+               device_create_file(&new_client->dev, &dev_attr_pwm3_enable);
+               device_create_file(&new_client->dev, &dev_attr_pwm1);
+               device_create_file(&new_client->dev, &dev_attr_pwm2);
+               device_create_file(&new_client->dev, &dev_attr_pwm3);
+       }
 
        if (data->type == it8712) {
                device_create_file_vrm(new_client);

-
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