From: Armin Wolf W_Armin@gmx.de
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=...
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commit c0d79987a0d82671bff374c07f2201f9bdf4aaa2 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: Armin Wolf W_Armin@gmx.de Reviewed-by: Pali Rohár pali@kernel.org Link: https://lore.kernel.org/r/20211021190531.17379-6-W_Armin@gmx.de Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/hwmon/dell-smm-hwmon.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c index 87f401100466..10c7b6295b02 100644 --- a/drivers/hwmon/dell-smm-hwmon.c +++ b/drivers/hwmon/dell-smm-hwmon.c @@ -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(®s) ? : i8k_get_fan_status(fan); + return i8k_smm(®s); }
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: