ChangeSet 1.2164, 2004/11/19 09:12:35-08:00, khali at linux-fr.org [PATCH] I2C: Do not register useless smsc47m1 While verifying my stack of patches against what you sent to Linus last week, I noticed this one. Looks like I simply forgot to send it to you, as I cannot find any trace of it in the lm_sensors mailing-list archives. The patch prevents an smsc47m1 device from being registered when no monitoring function is actually active within the chip. See this ticket for background: http://secure.netroedge.com/~lm78/readticket.cgi?ticket=1801 This is certainly better to explicitely fail in this case than leave the user with an empty sysfs directory (except for alarms), which tends to make him/her think of a driver bug, which it isn't (what it really is is a BIOS brokenness). Signed-off-by: Jean Delvare <khali at linux-fr.org> Signed-off-by: Greg Kroah-Hartman <greg at kroah.com> drivers/i2c/chips/smsc47m1.c | 29 +++++++++++++++++++++-------- 1 files changed, 21 insertions(+), 8 deletions(-) diff -Nru a/drivers/i2c/chips/smsc47m1.c b/drivers/i2c/chips/smsc47m1.c --- a/drivers/i2c/chips/smsc47m1.c 2004-11-19 11:40:54 -08:00 +++ b/drivers/i2c/chips/smsc47m1.c 2004-11-19 11:40:54 -08:00 @@ -394,6 +394,7 @@ struct i2c_client *new_client; struct smsc47m1_data *data; int err = 0; + int fan1, fan2, pwm1, pwm2; if (!i2c_is_isa_adapter(adapter)) { return 0; @@ -423,6 +424,22 @@ new_client->id = smsc47m1_id++; init_MUTEX(&data->update_lock); + /* If no function is properly configured, there's no point in + actually registering the chip. */ + fan1 = (smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(0)) & 0x05) + == 0x05; + fan2 = (smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(1)) & 0x05) + == 0x05; + pwm1 = (smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(0)) & 0x05) + == 0x04; + pwm2 = (smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(1)) & 0x05) + == 0x04; + if (!(fan1 || fan2 || pwm1 || pwm2)) { + dev_warn(&new_client->dev, "Device is not configured, will not use\n"); + err = -ENODEV; + goto error_free; + } + if ((err = i2c_attach_client(new_client))) goto error_free; @@ -434,8 +451,7 @@ function. */ smsc47m1_update_device(&new_client->dev, 1); - if ((smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(0)) & 0x05) - == 0x05) { + if (fan1) { device_create_file(&new_client->dev, &dev_attr_fan1_input); device_create_file(&new_client->dev, &dev_attr_fan1_min); device_create_file(&new_client->dev, &dev_attr_fan1_div); @@ -443,8 +459,7 @@ dev_dbg(&new_client->dev, "Fan 1 not enabled by hardware, " "skipping\n"); - if ((smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(1)) & 0x05) - == 0x05) { + if (fan2) { device_create_file(&new_client->dev, &dev_attr_fan2_input); device_create_file(&new_client->dev, &dev_attr_fan2_min); device_create_file(&new_client->dev, &dev_attr_fan2_div); @@ -452,15 +467,13 @@ dev_dbg(&new_client->dev, "Fan 2 not enabled by hardware, " "skipping\n"); - if ((smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(0)) & 0x05) - == 0x04) { + if (pwm1) { device_create_file(&new_client->dev, &dev_attr_pwm1); device_create_file(&new_client->dev, &dev_attr_pwm1_enable); } else dev_dbg(&new_client->dev, "PWM 1 not enabled by hardware, " "skipping\n"); - if ((smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(1)) & 0x05) - == 0x04) { + if (pwm2) { device_create_file(&new_client->dev, &dev_attr_pwm2); device_create_file(&new_client->dev, &dev_attr_pwm2_enable); } else
