ALSA: snd-usb: fix some typos in endpoint.c documentation

 * USB endpoint and its streaming.

 *

 * There are functions to activate and deactivate the streaming URBs and

 * optinal callbacks to let the pcm logic handle the actual content of the

 * optional callbacks to let the pcm logic handle the actual content of the

 * packets for playback and record. Thus, the bus streaming and the audio

 * handlers are fully decoupled.

 *

 * There are two different types of endpoints in for audio applications.

 * There are two different types of endpoints in audio applications.

 *

 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both

 * inbound and outbound traffic.

 *

 * SND_USB_ENDPOINT_TYPE_SYNC are for inbound traffic only and expect the

 * payload to carry Q16.16 formatted sync information (3 or 4 bytes).

 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and

 * expect the payload to carry Q10.14 / Q16.16 formatted sync information

 * (3 or 4 bytes).

 *

 * Each endpoint has to be configured (by calling

 * snd_usb_endpoint_set_params()) before it can be used.

 * Each endpoint has to be configured prior to being used by calling

 * snd_usb_endpoint_set_params().

 *

 * The model incorporates a reference counting, so that multiple users

 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and

 * only the first user will effectively start the URBs, and only the last

 * one will tear them down again.

 * one to stop it will tear the URBs down again.

 */

/*

/**

 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type

 *

 * @ep: The endpoint

 * @ep: The snd_usb_endpoint

 *

 * Determine whether an endpoint is driven by an implicit feedback

 * data endpoint source.

}

/*

 * Send output urbs that have been prepared previously. Urbs are dequeued

 * Send output urbs that have been prepared previously. URBs are dequeued

 * from ep->ready_playback_urbs and in case there there aren't any available

 * or there are no packets that have been prepared, this function does

 * nothing.

 *

 * The reason why the functionality of sending and preparing urbs is separated

 * is that host controllers don't guarantee an ordering in returing inbound

 * and outbound packets to their submitters.

 * The reason why the functionality of sending and preparing URBs is separated

 * is that host controllers don't guarantee the order in which they return

 * inbound and outbound packets to their submitters.

 *

 * This function is only used for implicit feedback endpoints. For endpoints

 * driven by sync endpoints, urbs are submitted from their completion handler.

 * driven by dedicated sync endpoints, URBs are immediately re-submitted

 * from their completion handler.

 */

static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)

{

}

/**

 * snd_usb_add_endpoint: Add an endpoint to an audio chip

 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip

 *

 * @chip: The chip

 * @alts: The USB host interface

}

/**

 * snd_usb_endpoint_set_params: configure an snd_endpoint

 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint

 *

 * @ep: the endpoint to configure

 * @ep: the snd_usb_endpoint to configure

 * @hw_params: the hardware parameters

 * @fmt: the USB audio format information

 * @sync_ep: the sync endpoint to use, if any

 *

 * Determine the number of of URBs to be used on this endpoint.

 * Determine the number of URBs to be used on this endpoint.

 * An endpoint must be configured before it can be started.

 * An endpoint that is already running can not be reconfigured.

 */

 * @ep: the endpoint to start

 *

 * A call to this function will increment the use count of the endpoint.

 * In case this not already running, the URBs for this endpoint will be

 * In case it is not already running, the URBs for this endpoint will be

 * submitted. Otherwise, this function does nothing.

 *

 * Must be balanced to calls of snd_usb_endpoint_stop().

	/*

	 * If this endpoint has a data endpoint as implicit feedback source,

	 * don't start the urbs here. Instead, mark them all as available,

	 * wait for the record urbs to arrive and queue from that context.

	 * wait for the record urbs to return and queue the playback urbs

	 * from that context.

	 */

	set_bit(EP_FLAG_RUNNING, &ep->flags);

 *

 * A call to this function will decrement the use count of the endpoint.

 * In case the last user has requested the endpoint stop, the URBs will

 * actually deactivated.

 * actually be deactivated.

 *

 * Must be balanced to calls of snd_usb_endpoint_start().

 */

	return -EBUSY;

}

/** snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint

/**

 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint

 *

 * @ep: the list header of the endpoint to free

 *

	/*

	 * In case the endpoint is operating in implicit feedback mode, prepare

	 * and a new outbound URB that has the same layout as the received

	 * packet and add it to the list of pending urbs.

	 * a new outbound URB that has the same layout as the received packet

	 * and add it to the list of pending urbs. queue_pending_output_urbs()

	 * will take care of them later.

	 */

	if (snd_usb_endpoint_implict_feedback_sink(ep) &&

	    ep->use_count != 0) {

		/*

		 * Iterate through the inbound packet and prepare the lengths

		 * for the output packet. The OUT packet we are about to send

		 * will have the same amount of payload than the IN packet we

		 * just received.

		 * will have the same amount of payload bytes than the IN

		 * packet we just received.

		 */

		out_packet->packets = in_ctx->packets;