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			48 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			48 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From: Mark Brown <broonie@kernel.org>
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| Date: Tue, 9 Dec 2014 19:46:56 +0000
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| Subject: [PATCH] spi: Check to see if the device is processing a message
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|  before we idle
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| 
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| cur_msg is updated under the queue lock and holds the message we are
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| currently processing. Since currently we only ever do removals in the
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| pump kthread it doesn't matter in what order we do things but we want
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| to be able to push things out from the submitting thread so pull the
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| check to see if we're currently handling a message before we check to
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| see if the queue is idle.
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| 
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| Signed-off-by: Mark Brown <broonie@kernel.org>
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| ---
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| 
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| --- a/drivers/spi/spi.c
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| +++ b/drivers/spi/spi.c
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| @@ -891,8 +891,16 @@ static void spi_pump_messages(struct kth
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|  	bool was_busy = false;
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|  	int ret;
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|  
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| -	/* Lock queue and check for queue work */
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| +	/* Lock queue */
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|  	spin_lock_irqsave(&master->queue_lock, flags);
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| +
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| +	/* Make sure we are not already running a message */
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| +	if (master->cur_msg) {
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| +		spin_unlock_irqrestore(&master->queue_lock, flags);
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| +		return;
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| +	}
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| +
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| +	/* Check if the queue is idle */
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|  	if (list_empty(&master->queue) || !master->running) {
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|  		if (!master->busy) {
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|  			spin_unlock_irqrestore(&master->queue_lock, flags);
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| @@ -916,11 +924,6 @@ static void spi_pump_messages(struct kth
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|  		return;
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|  	}
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|  
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| -	/* Make sure we are not already running a message */
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| -	if (master->cur_msg) {
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| -		spin_unlock_irqrestore(&master->queue_lock, flags);
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| -		return;
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| -	}
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|  	/* Extract head of queue */
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|  	master->cur_msg =
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|  		list_first_entry(&master->queue, struct spi_message, queue);
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