Commit d2757331 authored by Armin Wolf's avatar Armin Wolf Committed by Zheng Zengkai
Browse files

hwmon: (dell-smm) Speed up setting of fan speed 

stable inclusion
from stable-v5.10.101
commit ad53060bdfc34bb2fcc5bfff8a6f56bd425b964a
bugzilla: https://gitee.com/openeuler/kernel/issues/I5669Z

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ad53060bdfc34bb2fcc5bfff8a6f56bd425b964a



--------------------------------

commit c0d79987 upstream.

When setting the fan speed, i8k_set_fan() calls i8k_get_fan_status(),
causing an unnecessary SMM call since from the two users of this
function, only i8k_ioctl_unlocked() needs to know the new fan status
while dell_smm_write() ignores the new fan status.
Since SMM calls can be very slow while also making error reporting
difficult for dell_smm_write(), remove the function call from
i8k_set_fan() and call it separately in i8k_ioctl_unlocked().

Tested on a Dell Inspiron 3505.

Signed-off-by: default avatarArmin Wolf <W_Armin@gmx.de>
Reviewed-by: default avatarPali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20211021190531.17379-6-W_Armin@gmx.de


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarYu Liao <liaoyu15@huawei.com>
Reviewed-by: default avatarWei Li <liwei391@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 38d0a4d1

drivers/hwmon/dell-smm-hwmon.c

+8 −4
Original line number Diff line number Diff line
@@ -317,7 +317,7 @@ static int i8k_enable_fan_auto_mode(bool enable) 
}



/*

 * Set the fan speed (off, low, high). Returns the new fan status.

 * Set the fan speed (off, low, high, ...).

 */

static int i8k_set_fan(int fan, int speed)

{
@@ -329,7 +329,7 @@ static int i8k_set_fan(int fan, int speed) 
	speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);

	regs.ebx = (fan & 0xff) | (speed << 8);



	return i8k_smm(&regs) ? : i8k_get_fan_status(fan);

	return i8k_smm(&regs);

}



static int i8k_get_temp_type(int sensor)
@@ -443,7 +443,7 @@ static int 
i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)

{

	int val = 0;

	int speed;

	int speed, err;

	unsigned char buff[16];

	int __user *argp = (int __user *)arg;
@@ -504,7 +504,11 @@ i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg) 
		if (copy_from_user(&speed, argp + 1, sizeof(int)))

			return -EFAULT;



		val = i8k_set_fan(val, speed);

		err = i8k_set_fan(val, speed);

		if (err < 0)

			return err;



		val = i8k_get_fan_status(val);

		break;



	default: