Re: [PATCH 2/3] platform/x86: thinkpad_acpi: convert conditional mutex locks to ACQUIRE_ERR()

["Mark Pearson" <mpearson-lenovo@squebb.ca>]

Thanks Dmitry,

On Thu, Aug 6, 2026, at 2:19 AM, Dmitry Torokhov wrote:
> Convert conditional mutex_lock_killable() and mutex_lock_interruptible()
> calls to ACQUIRE() and ACQUIRE_ERR() from linux/cleanup.h.
>
> This eliminates explicit mutex_unlock() calls on return paths and
> simplifies error handling across hotkey, brightness, volume, fan, and
> dytc functions.
>
> Assisted-by: Antigravity:gemini-3.6-flash
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
>  drivers/platform/x86/lenovo/thinkpad_acpi.c | 153 ++++++++++----------
>  1 file changed, 76 insertions(+), 77 deletions(-)
>
> diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c 
> b/drivers/platform/x86/lenovo/thinkpad_acpi.c
> index beb85ea1103b..0d0d6fe7eecd 100644
> --- a/drivers/platform/x86/lenovo/thinkpad_acpi.c
> +++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c
> @@ -2671,8 +2671,10 @@ static ssize_t hotkey_mask_store(struct device 
> *dev,
>  	if (parse_strtoul(buf, 0xffffffffUL, &t))
>  		return -EINVAL;
> 
> -	if (mutex_lock_killable(&hotkey_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&hotkey_mutex);
> +	res = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (res)
> +		return res;
> 
>  	res = hotkey_user_mask_set(t);
> 
> @@ -2680,8 +2682,6 @@ static ssize_t hotkey_mask_store(struct device *dev,
>  	hotkey_poll_setup(true);
>  #endif
> 
> -	mutex_unlock(&hotkey_mutex);
> -
>  	tpacpi_disclose_usertask("hotkey_mask", "set to 0x%08lx\n", t);
> 
>  	return (res) ? res : count;
> @@ -2767,8 +2767,10 @@ static ssize_t hotkey_source_mask_store(struct 
> device *dev,
>  		((t & ~TPACPI_HKEY_NVRAM_KNOWN_MASK) != 0))
>  		return -EINVAL;
> 
> -	if (mutex_lock_killable(&hotkey_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&hotkey_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	HOTKEY_CONFIG_CRITICAL_START
>  	hotkey_source_mask = t;
> @@ -2782,8 +2784,6 @@ static ssize_t hotkey_source_mask_store(struct 
> device *dev,
>  	r_ev = hotkey_driver_mask & ~(hotkey_acpi_mask & hotkey_all_mask)
>  		& ~hotkey_source_mask & TPACPI_HKEY_NVRAM_KNOWN_MASK;
> 
> -	mutex_unlock(&hotkey_mutex);
> -
>  	if (rc < 0)
>  		pr_err("hotkey_source_mask: failed to update the firmware event mask!\n");
> 
> @@ -2811,18 +2811,19 @@ static ssize_t hotkey_poll_freq_store(struct 
> device *dev,
>  			    const char *buf, size_t count)
>  {
>  	unsigned long t;
> +	int err;
> 
>  	if (parse_strtoul(buf, 25, &t))
>  		return -EINVAL;
> 
> -	if (mutex_lock_killable(&hotkey_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&hotkey_mutex);
> +	err = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (err)
> +		return err;
> 
>  	hotkey_poll_set_freq(t);
>  	hotkey_poll_setup(true);
> 
> -	mutex_unlock(&hotkey_mutex);
> -
>  	tpacpi_disclose_usertask("hotkey_poll_freq", "set to %lu\n", t);
> 
>  	return count;
> @@ -3995,12 +3996,13 @@ static int hotkey_read(struct seq_file *m)
>  		return 0;
>  	}
> 
> -	if (mutex_lock_killable(&hotkey_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&hotkey_mutex);
> +	res = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (res)
> +		return res;
>  	res = hotkey_status_get(&status);
>  	if (!res)
>  		res = hotkey_mask_get();
> -	mutex_unlock(&hotkey_mutex);
>  	if (res)
>  		return res;
> 
> @@ -4033,8 +4035,10 @@ static int hotkey_write(char *buf)
>  	if (!tp_features.hotkey)
>  		return -ENODEV;
> 
> -	if (mutex_lock_killable(&hotkey_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&hotkey_mutex);
> +	res = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (res)
> +		return res;
> 
>  	mask = hotkey_user_mask;
> 
> @@ -4053,8 +4057,7 @@ static int hotkey_write(char *buf)
>  		} else if (sscanf(cmd, "%x", &mask) == 1) {
>  			/* mask set */
>  		} else {
> -			res = -EINVAL;
> -			goto errexit;
> +			return -EINVAL;
>  		}
>  	}
> 
> @@ -4064,8 +4067,6 @@ static int hotkey_write(char *buf)
>  		res = hotkey_user_mask_set(mask);
>  	}
> 
> -errexit:
> -	mutex_unlock(&hotkey_mutex);
>  	return res;
>  }
> 
> @@ -6460,11 +6461,12 @@ static void tpacpi_brightness_checkpoint_nvram(void)
>  	vdbg_printk(TPACPI_DBG_BRGHT,
>  		"trying to checkpoint backlight level to NVRAM...\n");
> 
> -	if (mutex_lock_killable(&brightness_mutex) < 0)
> +	ACQUIRE(mutex_kill, guard)(&brightness_mutex);
> +	if (ACQUIRE_ERR(mutex_kill, &guard))
>  		return;
> 
>  	if (unlikely(!acpi_ec_read(TP_EC_BACKLIGHT, &lec)))
> -		goto unlock;
> +		return;
>  	lec &= TP_EC_BACKLIGHT_LVLMSK;
>  	b_nvram = nvram_read_byte(TP_NVRAM_ADDR_BRIGHTNESS);
> 
> @@ -6482,9 +6484,6 @@ static void tpacpi_brightness_checkpoint_nvram(void)
>  		vdbg_printk(TPACPI_DBG_BRGHT,
>  			   "NVRAM backlight level already is %u (0x%02x)\n",
>  			   (unsigned int) lec, (unsigned int) b_nvram);
> -
> -unlock:
> -	mutex_unlock(&brightness_mutex);
>  }
> 
> 
> @@ -6562,8 +6561,9 @@ static int brightness_set(unsigned int value)
>  	vdbg_printk(TPACPI_DBG_BRGHT,
>  			"set backlight level to %d\n", value);
> 
> -	res = mutex_lock_killable(&brightness_mutex);
> -	if (res < 0)
> +	ACQUIRE(mutex_kill, guard)(&brightness_mutex);
> +	res = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (res)
>  		return res;
> 
>  	switch (brightness_mode) {
> @@ -6578,7 +6578,6 @@ static int brightness_set(unsigned int value)
>  		res = -ENXIO;
>  	}
> 
> -	mutex_unlock(&brightness_mutex);
>  	return res;
>  }
> 
> @@ -6601,16 +6600,14 @@ static int brightness_get(struct backlight_device *bd)
>  {
>  	int status, res;
> 
> -	res = mutex_lock_killable(&brightness_mutex);
> -	if (res < 0)
> -		return 0;
> +	ACQUIRE(mutex_kill, guard)(&brightness_mutex);
> +	res = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (res)
> +		return res;
> 
>  	res = tpacpi_brightness_get_raw(&status);
> -
> -	mutex_unlock(&brightness_mutex);
> -
>  	if (res < 0)
> -		return 0;
> +		return res;
> 
>  	return status & TP_EC_BACKLIGHT_LVLMSK;
>  }
> @@ -7073,11 +7070,12 @@ static void tpacpi_volume_checkpoint_nvram(void)
>  	else
>  		ec_mask = TP_EC_AUDIO_MUTESW_MSK | TP_EC_AUDIO_LVL_MSK;
> 
> -	if (mutex_lock_killable(&volume_mutex) < 0)
> +	ACQUIRE(mutex_kill, guard)(&volume_mutex);
> +	if (ACQUIRE_ERR(mutex_kill, &guard))
>  		return;
> 
>  	if (unlikely(!acpi_ec_read(TP_EC_AUDIO, &lec)))
> -		goto unlock;
> +		return;
>  	lec &= ec_mask;
>  	b_nvram = nvram_read_byte(TP_NVRAM_ADDR_MIXER);
> 
> @@ -7094,9 +7092,6 @@ static void tpacpi_volume_checkpoint_nvram(void)
>  			   "NVRAM mixer status already is 0x%02x (0x%02x)\n",
>  			   (unsigned int) lec, (unsigned int) b_nvram);
>  	}
> -
> -unlock:
> -	mutex_unlock(&volume_mutex);
>  }
> 
>  static int volume_get_status_ec(u8 *status)
> @@ -7145,12 +7140,14 @@ static int __volume_set_mute_ec(const bool mute)
>  	int rc;
>  	u8 s, n;
> 
> -	if (mutex_lock_killable(&volume_mutex) < 0)
> -		return -EINTR;
> +	ACQUIRE(mutex_kill, guard)(&volume_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	rc = volume_get_status_ec(&s);
>  	if (rc)
> -		goto unlock;
> +		return rc;
> 
>  	n = (mute) ? s | TP_EC_AUDIO_MUTESW_MSK :
>  		     s & ~TP_EC_AUDIO_MUTESW_MSK;
> @@ -7161,8 +7158,6 @@ static int __volume_set_mute_ec(const bool mute)
>  			rc = 1;
>  	}
> 
> -unlock:
> -	mutex_unlock(&volume_mutex);
>  	return rc;
>  }
> 
> @@ -7193,12 +7188,14 @@ static int __volume_set_volume_ec(const u8 vol)
>  	if (vol > TP_EC_VOLUME_MAX)
>  		return -EINVAL;
> 
> -	if (mutex_lock_killable(&volume_mutex) < 0)
> -		return -EINTR;
> +	ACQUIRE(mutex_kill, guard)(&volume_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	rc = volume_get_status_ec(&s);
>  	if (rc)
> -		goto unlock;
> +		return rc;
> 
>  	n = (s & ~TP_EC_AUDIO_LVL_MSK) | vol;
> 
> @@ -7208,8 +7205,6 @@ static int __volume_set_volume_ec(const u8 vol)
>  			rc = 1;
>  	}
> 
> -unlock:
> -	mutex_unlock(&volume_mutex);
>  	return rc;
>  }
> 
> @@ -8113,13 +8108,14 @@ static int fan_get_status_safe(u8 *status)
>  	int rc;
>  	u8 s;
> 
> -	if (mutex_lock_killable(&fan_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&fan_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
>  	rc = fan_get_status(&s);
>  	/* NS EC doesn't have register with level settings */
>  	if (!rc && !fan_with_ns_addr)
>  		fan_update_desired_level(s);
> -	mutex_unlock(&fan_mutex);
> 
>  	if (rc)
>  		return rc;
> @@ -8312,8 +8308,10 @@ static int fan_set_level_safe(int level)
>  	if (!fan_control_allowed)
>  		return -EPERM;
> 
> -	if (mutex_lock_killable(&fan_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&fan_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	if (level == TPACPI_FAN_LAST_LEVEL)
>  		level = fan_control_desired_level;
> @@ -8322,7 +8320,6 @@ static int fan_set_level_safe(int level)
>  	if (!rc)
>  		fan_update_desired_level(level);
> 
> -	mutex_unlock(&fan_mutex);
>  	return rc;
>  }
> 
> @@ -8334,8 +8331,10 @@ static int fan_set_enable(void)
>  	if (!fan_control_allowed)
>  		return -EPERM;
> 
> -	if (mutex_lock_killable(&fan_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&fan_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	switch (fan_control_access_mode) {
>  	case TPACPI_FAN_WR_ACPI_FANS:
> @@ -8391,8 +8390,6 @@ static int fan_set_enable(void)
>  		rc = -ENXIO;
>  	}
> 
> -	mutex_unlock(&fan_mutex);
> -
>  	if (!rc)
>  		vdbg_printk(TPACPI_DBG_FAN,
>  			"fan control: set fan control register to 0x%02x\n",
> @@ -8407,8 +8404,10 @@ static int fan_set_disable(void)
>  	if (!fan_control_allowed)
>  		return -EPERM;
> 
> -	if (mutex_lock_killable(&fan_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&fan_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	rc = 0;
>  	switch (fan_control_access_mode) {
> @@ -8453,7 +8452,6 @@ static int fan_set_disable(void)
>  		vdbg_printk(TPACPI_DBG_FAN,
>  			"fan control: set fan control register to 0\n");
> 
> -	mutex_unlock(&fan_mutex);
>  	return rc;
>  }
> 
> @@ -8464,8 +8462,10 @@ static int fan_set_speed(int speed)
>  	if (!fan_control_allowed)
>  		return -EPERM;
> 
> -	if (mutex_lock_killable(&fan_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&fan_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	rc = 0;
>  	switch (fan_control_access_mode) {
> @@ -8499,7 +8499,6 @@ static int fan_set_speed(int speed)
>  		rc = -ENXIO;
>  	}
> 
> -	mutex_unlock(&fan_mutex);
>  	return rc;
>  }
> 
> @@ -8659,8 +8658,10 @@ static ssize_t fan_pwm1_store(struct device *dev,
>  	/* scale down from 0-255 to 0-7 */
>  	newlevel = (s >> 5) & 0x07;
> 
> -	if (mutex_lock_killable(&fan_mutex))
> -		return -ERESTARTSYS;
> +	ACQUIRE(mutex_kill, guard)(&fan_mutex);
> +	rc = ACQUIRE_ERR(mutex_kill, &guard);
> +	if (rc)
> +		return rc;
> 
>  	rc = fan_get_status(&status);
>  	if (!rc && (status &
> @@ -8674,7 +8675,6 @@ static ssize_t fan_pwm1_store(struct device *dev,
>  		}
>  	}
> 
> -	mutex_unlock(&fan_mutex);
>  	return (rc) ? rc : count;
>  }
> 
> @@ -10522,13 +10522,14 @@ static int dytc_profile_set(struct device *dev,
>  	int output;
>  	int err;
> 
> -	err = mutex_lock_interruptible(&dytc_mutex);
> +	ACQUIRE(mutex_intr, guard)(&dytc_mutex);
> +	err = ACQUIRE_ERR(mutex_intr, &guard);
>  	if (err)
>  		return err;
> 
>  	err = convert_profile_to_dytc(profile, &perfmode);
>  	if (err)
> -		goto unlock;
> +		return err;
> 
>  	if (dytc_capabilities & BIT(DYTC_FC_MMC)) {
>  		if (profile == PLATFORM_PROFILE_BALANCED) {
> @@ -10540,18 +10541,18 @@ static int dytc_profile_set(struct device 
> *dev,
>  			 */
>  			err = dytc_cql_command(DYTC_CMD_RESET, &output);
>  			if (err)
> -				goto unlock;
> +				return err;
>  		} else {
>  			/* Determine if we are in CQL mode. This alters the commands we do 
> */
>  			err = dytc_cql_command(DYTC_SET_COMMAND(DYTC_FUNCTION_MMC, 
> perfmode, 1),
>  						&output);
>  			if (err)
> -				goto unlock;
> +				return err;
>  		}
>  	} else if (dytc_capabilities & BIT(DYTC_FC_PSC)) {
>  		err = dytc_command(DYTC_SET_COMMAND(DYTC_FUNCTION_PSC, perfmode, 1), 
> &output);
>  		if (err)
> -			goto unlock;
> +			return err;
> 
>  		/* system supports AMT, activate it when on balanced */
>  		if (dytc_capabilities & BIT(DYTC_FC_AMT))
> @@ -10559,8 +10560,6 @@ static int dytc_profile_set(struct device *dev,
>  	}
>  	/* Success - update current profile */
>  	dytc_current_profile = profile;
> -unlock:
> -	mutex_unlock(&dytc_mutex);
>  	return err;
>  }
> 
> -- 
> 2.55.0.679.g6767b8d81c-goog

I've not come across ACQUIRE & ACQUIRE_KILL before - so this was all new to me.
I went and did some reading and all the above looks good to me, and looks like a valid clean-up.
But my reviewed-by tag does come with reduced value....

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>

Thanks for the learning experience. I will aim to go and try this out (and the other patches in the series) on some HW in the near future.

Mark