Re: [PATCH v4 3/4] iio: ssp_sensors: ssp_spi: use guard() to release mutexes

[Andy Shevchenko]

On Thu, Mar 26, 2026 at 01:48:14PM +0530, Sanjay Chitroda wrote:

> Replace explicit mutex_lock() and mutex_unlock() with the guard() macro
> for cleaner and safer mutex handling.

NAK. Please, be very careful when do such changes.

...

>  	msg->done = done;
>  
> -	mutex_lock(&data->comm_lock);
> +	guard(mutex)(&data->comm_lock);
>  
>  	status = ssp_check_lines(data, false);
> -	if (status < 0)
> -		goto _error_locked;
> +	if (status < 0) {
> +		data->timeout_cnt++;
> +		return status;
> +	}
>  
>  	status = spi_write(data->spi, msg->buffer, SSP_HEADER_SIZE);
>  	if (status < 0) {
>  		gpiod_set_value_cansleep(data->ap_mcu_gpiod, 1);
>  		dev_err(SSP_DEV, "%s spi_write fail\n", __func__);
> -		goto _error_locked;
> +		data->timeout_cnt++;
> +		return status;
>  	}
>  
>  	if (!use_no_irq) {
> -		mutex_lock(&data->pending_lock);
> +		guard(mutex)(&data->pending_lock);
>  		list_add_tail(&msg->list, &data->pending_list);
> -		mutex_unlock(&data->pending_lock);
>  	}
>  
>  	status = ssp_check_lines(data, true);
>  	if (status < 0) {
>  		if (!use_no_irq) {
> -			mutex_lock(&data->pending_lock);
> +			guard(mutex)(&data->pending_lock);
>  			list_del(&msg->list);
> -			mutex_unlock(&data->pending_lock);
>  		}
> -		goto _error_locked;
> +		data->timeout_cnt++;
> +		return status;
>  	}

> -	mutex_unlock(&data->comm_lock);
> -

Pzzz! See what you are doing here...

>  	if (!use_no_irq && done)
>  		if (wait_for_completion_timeout(done,
>  						msecs_to_jiffies(timeout)) ==
>  		    0) {
> -			mutex_lock(&data->pending_lock);
> +			guard(mutex)(&data->pending_lock);
>  			list_del(&msg->list);
> -			mutex_unlock(&data->pending_lock);
>  
>  			data->timeout_cnt++;
>  			return -ETIMEDOUT;
>  		}
>  
>  	return 0;
> -
> -_error_locked:
> -	mutex_unlock(&data->comm_lock);
> -	data->timeout_cnt++;
> -	return status;
>  }

-- 
With Best Regards,
Andy Shevchenko