linux-stable/sound/usb/endpoint.h
Takashi Iwai 00272c6182 ALSA: usb-audio: Avoid unnecessary interface re-setup
The current endpoint handling assumed (more or less) a unique 1:1
relation between the endpoint and the iface/altset.  The exception was
the sync EP without the implicit feedback which has usually the
secondary EP of the same altset.  This works fine for most devices,
but it turned out that some unusual devices like Pinoeer's ones have
both playback and capture endpoints in the same iface/altsetting and
use both for the implicit feedback mode.  For handling such a case, we
need to extend the endpoint management to take the shared interface
into account.

This patch does that: it adds a new object snd_usb_iface_ref for
managing the reference counts of the each USB interface that is used
by each endpoint.  The interface setup is performed only once for the
(sharing) endpoints, and the doubly initialization is avoided.

Along with this, the resource release of endpoints and interface
refcounts are put into a single function, snd_usb_endpoint_free_all()
instead of looping in the caller side.

Fixes: bf6313a0ff ("ALSA: usb-audio: Refactor endpoint management")
Link: https://lore.kernel.org/r/20210108075219.21463-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-01-08 23:43:37 +01:00

51 lines
2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __USBAUDIO_ENDPOINT_H
#define __USBAUDIO_ENDPOINT_H
#define SND_USB_ENDPOINT_TYPE_DATA 0
#define SND_USB_ENDPOINT_TYPE_SYNC 1
struct snd_usb_endpoint *snd_usb_get_endpoint(struct snd_usb_audio *chip,
int ep_num);
int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type);
struct snd_usb_endpoint *
snd_usb_endpoint_open(struct snd_usb_audio *chip,
const struct audioformat *fp,
const struct snd_pcm_hw_params *params,
bool is_sync_ep);
void snd_usb_endpoint_close(struct snd_usb_audio *chip,
struct snd_usb_endpoint *ep);
int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
struct snd_usb_endpoint *ep);
void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep);
bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
struct snd_usb_endpoint *ep,
const struct audioformat *fp,
const struct snd_pcm_hw_params *params);
void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,
struct snd_usb_endpoint *data_ep,
struct snd_usb_endpoint *sync_ep);
void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,
void (*prepare)(struct snd_usb_substream *subs,
struct urb *urb),
void (*retire)(struct snd_usb_substream *subs,
struct urb *urb),
struct snd_usb_substream *data_subs);
int snd_usb_endpoint_start(struct snd_usb_endpoint *ep);
void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep);
void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep);
void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep);
int snd_usb_endpoint_activate(struct snd_usb_endpoint *ep);
void snd_usb_endpoint_release(struct snd_usb_endpoint *ep);
void snd_usb_endpoint_free_all(struct snd_usb_audio *chip);
int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep);
int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *ctx, int idx);
#endif /* __USBAUDIO_ENDPOINT_H */