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Commit 260eaba4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'hwmon-for-linus-v4.7-rc5' of... 

Merge tag 'hwmon-for-linus-v4.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fix from Guenter Roeck:
 "Improve fan type detection for dell-smm to prevent kernel hang"

* tag 'hwmon-for-linus-v4.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (dell-smm) Cache fan_type() calls and change fan detection
parents ed13fbbf 5ce91714

drivers/hwmon/dell-smm-hwmon.c

+20 −5
Original line number Diff line number Diff line
@@ -238,7 +238,7 @@ static int i8k_get_fan_speed(int fan) 
/*

 * Read the fan type.

 */

static int i8k_get_fan_type(int fan)

static int _i8k_get_fan_type(int fan)

{

	struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
@@ -249,6 +249,17 @@ static int i8k_get_fan_type(int fan) 
	return i8k_smm(&regs) ? : regs.eax & 0xff;

}



static int i8k_get_fan_type(int fan)

{

	/* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */

	static int types[2] = { INT_MIN, INT_MIN };



	if (types[fan] == INT_MIN)

		types[fan] = _i8k_get_fan_type(fan);



	return types[fan];

}



/*

 * Read the fan nominal rpm for specific fan speed.

 */
@@ -782,12 +793,16 @@ static int __init i8k_init_hwmon(void) 
	if (err >= 0)

		i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;



	/* First fan attributes, if fan type is OK */

	/* First fan attributes, if fan status or type is OK */

	err = i8k_get_fan_status(0);

	if (err < 0)

		err = i8k_get_fan_type(0);

	if (err >= 0)

		i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;



	/* Second fan attributes, if fan type is OK */

	/* Second fan attributes, if fan status or type is OK */

	err = i8k_get_fan_status(1);

	if (err < 0)

		err = i8k_get_fan_type(1);

	if (err >= 0)

		i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;