From 158ce07564b68d4215b9560213a089d6f7c5a4ea Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sun, 17 Jun 2007 16:09:12 +0200 Subject: [PATCH] hwmon/w83627ehf: Preserve speed reading when changing fan min The w83627ehf driver changes the fan clock divider automatically when a new min fan speed is set. It is supposed to preserve the fan speed reading while doing so, bug doesn't really. Fix it. Signed-off-by: Jean Delvare Signed-off-by: Mark M. Hoffman --- drivers/hwmon/w83627ehf.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c index 30a76404f0a..f4d850c7158 100644 --- a/drivers/hwmon/w83627ehf.c +++ b/drivers/hwmon/w83627ehf.c @@ -716,10 +716,15 @@ store_fan_min(struct device *dev, struct device_attribute *attr, /* Write both the fan clock divider (if it changed) and the new fan min (unconditionally) */ if (new_div != data->fan_div[nr]) { - if (new_div > data->fan_div[nr]) - data->fan[nr] >>= (data->fan_div[nr] - new_div); - else - data->fan[nr] <<= (new_div - data->fan_div[nr]); + /* Preserve the fan speed reading */ + if (data->fan[nr] != 0xff) { + if (new_div > data->fan_div[nr]) + data->fan[nr] >>= new_div - data->fan_div[nr]; + else if (data->fan[nr] & 0x80) + data->fan[nr] = 0xff; + else + data->fan[nr] <<= data->fan_div[nr] - new_div; + } dev_dbg(dev, "fan%u clock divider changed from %u to %u\n", nr + 1, div_from_reg(data->fan_div[nr]), -- 2.20.1