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Commit 723493ca authored by Pali Rohár's avatar Pali Rohár Committed by Greg Kroah-Hartman
Browse files

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: default avatarPali Rohár <pali.rohar@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ca4f8280

drivers/char/i8k.c

+10 −6
Original line number Original line Diff line number Diff line
@@ -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 */