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| author | Pali Rohár <pali.rohar@gmail.com> | 2014-11-18 17:56:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-27 06:29:36 +0300 |
| commit | 723493ca59c8d81fed3e7f261165fee493a29ffa (patch) | |
| tree | 966c77b05f2fbdb1e26f439c6587734b8c81baa0 /drivers/char/i8k.c | |
| parent | ca4f8280ff227e215f44e10f8f110b4c882b084b (diff) | |
| download | linux-723493ca59c8d81fed3e7f261165fee493a29ffa.tar.xz | |
i8k: Fix temperature bug handling in i8k_get_temp()
Static array prev[] was incorrectly initialized. It should be initialized to
some "invalid" temperature value (above I8K_MAX_TEMP).
Next, function should store "invalid" value to prev[] (above I8K_MAX_TEMP),
not valid (= I8K_MAX_TEMP) because whole temperature bug handling will not
work.
And last part, to not break existing detection of temperature sensors, register
them also if i8k report too high temperature (above I8K_MAX_TEMP). This is
needed because some sensors are sometimes turned off (e.g sensor on GPU which
can be turned off/on) and in this case SMM report too high value.
To prevent reporting "invalid" values to userspace, return -EINVAL. In this case
sensors which are currently turned off (e.g optimus/powerexpress/enduro gpu)
are reported as "N/A" by lm-sensors package.
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/char/i8k.c')
| -rw-r--r-- | drivers/char/i8k.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c index 7272b08dbd6c..e34a019eb930 100644 --- a/drivers/char/i8k.c +++ b/drivers/char/i8k.c @@ -298,7 +298,7 @@ static int i8k_get_temp(int sensor) int temp; #ifdef I8K_TEMPERATURE_BUG - static int prev[4]; + static int prev[4] = { I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1 }; #endif regs.ebx = sensor & 0xff; rc = i8k_smm(®s); @@ -317,10 +317,12 @@ static int i8k_get_temp(int sensor) */ if (temp > I8K_MAX_TEMP) { temp = prev[sensor]; - prev[sensor] = I8K_MAX_TEMP; + prev[sensor] = I8K_MAX_TEMP+1; } else { prev[sensor] = temp; } + if (temp > I8K_MAX_TEMP) + return -ERANGE; #endif return temp; @@ -499,6 +501,8 @@ static ssize_t i8k_hwmon_show_temp(struct device *dev, int temp; temp = i8k_get_temp(index); + if (temp == -ERANGE) + return -EINVAL; if (temp < 0) return temp; return sprintf(buf, "%d\n", temp * 1000); @@ -610,17 +614,17 @@ static int __init i8k_init_hwmon(void) /* CPU temperature attributes, if temperature reading is OK */ err = i8k_get_temp(0); - if (err >= 0) + if (err >= 0 || err == -ERANGE) i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1; /* check for additional temperature sensors */ err = i8k_get_temp(1); - if (err >= 0) + if (err >= 0 || err == -ERANGE) i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2; err = i8k_get_temp(2); - if (err >= 0) + if (err >= 0 || err == -ERANGE) i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3; err = i8k_get_temp(3); - if (err >= 0) + if (err >= 0 || err == -ERANGE) i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4; /* Left fan attributes, if left fan is present */ |