i8k: Fix temperature bug handling in i8k_get_temp() (723493ca) · Commits · 戴 / test

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>

drivers/char/i8k.c

+10 −6

Original line number	Diff line number	Diff line
		@@ -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(&regs);
		@@ -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 */

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