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i8k: Fix temperature bug handling in i8k_get_temp()

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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>
This commit is contained in:
Pali Rohár 2014-11-18 15:56:54 +01:00 committed by Greg Kroah-Hartman
parent ca4f8280ff
commit 723493ca59
1 changed files with 10 additions and 6 deletions
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16
drivers/char/i8k.c
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@ -298,7 +298,7 @@ static int i8k_get_temp(int sensor)
int temp; int temp;
#ifdef I8K_TEMPERATURE_BUG #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 #endif
regs.ebx = sensor & 0xff; regs.ebx = sensor & 0xff;
rc = i8k_smm(&regs); rc = i8k_smm(&regs);
@ -317,10 +317,12 @@ static int i8k_get_temp(int sensor)
*/ */
if (temp > I8K_MAX_TEMP) { if (temp > I8K_MAX_TEMP) {
temp = prev[sensor]; temp = prev[sensor];
prev[sensor] = I8K_MAX_TEMP; prev[sensor] = I8K_MAX_TEMP+1;
} else { } else {
prev[sensor] = temp; prev[sensor] = temp;
} }
if (temp > I8K_MAX_TEMP)
return -ERANGE;
#endif #endif
return temp; return temp;
@ -499,6 +501,8 @@ static ssize_t i8k_hwmon_show_temp(struct device *dev,
int temp; int temp;
temp = i8k_get_temp(index); temp = i8k_get_temp(index);
if (temp == -ERANGE)
return -EINVAL;
if (temp < 0) if (temp < 0)
return temp; return temp;
return sprintf(buf, "%d\n", temp * 1000); 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 */ /* CPU temperature attributes, if temperature reading is OK */
err = i8k_get_temp(0); err = i8k_get_temp(0);
if (err >= 0) if (err >= 0 || err == -ERANGE)
i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1; i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
/* check for additional temperature sensors */ /* check for additional temperature sensors */
err = i8k_get_temp(1); err = i8k_get_temp(1);
if (err >= 0) if (err >= 0 || err == -ERANGE)
i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2; i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
err = i8k_get_temp(2); err = i8k_get_temp(2);
if (err >= 0) if (err >= 0 || err == -ERANGE)
i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3; i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
err = i8k_get_temp(3); err = i8k_get_temp(3);
if (err >= 0) if (err >= 0 || err == -ERANGE)
i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4; i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
/* Left fan attributes, if left fan is present */ /* Left fan attributes, if left fan is present */