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		813a17cab9
		
	
	
	
	
		
			
			While draining a stream, ALSA PCM core stops the stream by issuing snd_pcm_stop() after all data has been sent out. And, at PCM trigger stop, currently USB-audio driver kills the in-flight URBs explicitly, then at sync-stop ops, sync with the finish of all remaining URBs. This might result in a drop of the drained samples as most of USB-audio devices / hosts allow relatively long in-flight samples (as a sort of FIFO). For avoiding the trimming, this patch changes the stream-stop behavior during PCM draining state. Under that condition, the pending URBs won't be killed. The leftover in-flight URBs are caught by the sync-stop operation that shall be performed after the trigger-stop operation. Link: https://lore.kernel.org/r/20210929080844.11583-10-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
		
			
				
	
	
		
			56 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			56 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef __USBAUDIO_ENDPOINT_H
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| #define __USBAUDIO_ENDPOINT_H
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| 
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| #define SND_USB_ENDPOINT_TYPE_DATA     0
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| #define SND_USB_ENDPOINT_TYPE_SYNC     1
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| 
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| struct snd_usb_endpoint *snd_usb_get_endpoint(struct snd_usb_audio *chip,
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| 					      int ep_num);
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| 
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| int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type);
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| 
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| struct snd_usb_endpoint *
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| snd_usb_endpoint_open(struct snd_usb_audio *chip,
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| 		      const struct audioformat *fp,
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| 		      const struct snd_pcm_hw_params *params,
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| 		      bool is_sync_ep);
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| void snd_usb_endpoint_close(struct snd_usb_audio *chip,
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| 			    struct snd_usb_endpoint *ep);
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| int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
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| 			       struct snd_usb_endpoint *ep);
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| int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock);
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| 
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| bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
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| 				 struct snd_usb_endpoint *ep,
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| 				 const struct audioformat *fp,
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| 				 const struct snd_pcm_hw_params *params);
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| 
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| void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,
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| 			       struct snd_usb_endpoint *data_ep,
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| 			       struct snd_usb_endpoint *sync_ep);
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| void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,
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| 				   int (*prepare)(struct snd_usb_substream *subs,
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| 						  struct urb *urb,
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| 						  bool in_stream_lock),
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| 				   void (*retire)(struct snd_usb_substream *subs,
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| 						  struct urb *urb),
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| 				   struct snd_usb_substream *data_subs);
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| 
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| int snd_usb_endpoint_start(struct snd_usb_endpoint *ep);
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| void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool keep_pending);
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| void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep);
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| void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep);
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| int  snd_usb_endpoint_activate(struct snd_usb_endpoint *ep);
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| void snd_usb_endpoint_release(struct snd_usb_endpoint *ep);
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| void snd_usb_endpoint_free_all(struct snd_usb_audio *chip);
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| 
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| int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep);
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| int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,
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| 				      struct snd_urb_ctx *ctx, int idx,
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| 				      unsigned int avail);
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| void snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint *ep,
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| 				       bool in_stream_lock);
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| 
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| #endif /* __USBAUDIO_ENDPOINT_H */
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