From c7474d09777c3d321f9f7f6a416f276204926c54 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 23 Nov 2020 09:53:11 +0100 Subject: ALSA: usb-audio: Add snd_usb_get_endpoint() helper Factor out the code to obtain snd_usb_endpoint object matching with the given endpoint. It'll be used in the later patch to add the implicit feedback hw-constraint. No functional change by this patch itself. Tested-by: Keith Milner Tested-by: Dylan Robinson Link: https://lore.kernel.org/r/20201123085347.19667-6-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/usb/endpoint.c | 36 +++++++++++++++++++++++++++--------- sound/usb/endpoint.h | 4 ++++ 2 files changed, 31 insertions(+), 9 deletions(-) diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index e2f9ce2f5b8b..cf00871fd278 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -439,6 +439,26 @@ exit_clear: clear_bit(ctx->index, &ep->active_mask); } +/* + * Get the existing endpoint object corresponding EP, iface and alt numbers + * Returns NULL if not present. + * Call inside chip->mutex locking for avoiding the race. + */ +struct snd_usb_endpoint * +snd_usb_get_endpoint(struct snd_usb_audio *chip, + int ep_num, int iface, int altsetting) +{ + struct snd_usb_endpoint *ep; + + list_for_each_entry(ep, &chip->ep_list, list) { + if (ep->ep_num == ep_num && + ep->iface == iface && + ep->altsetting == altsetting) + return ep; + } + return NULL; +} + /** * snd_usb_add_endpoint: Add an endpoint to an USB audio chip * @@ -470,15 +490,13 @@ struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip, mutex_lock(&chip->mutex); - list_for_each_entry(ep, &chip->ep_list, list) { - if (ep->ep_num == ep_num && - ep->iface == alts->desc.bInterfaceNumber && - ep->altsetting == alts->desc.bAlternateSetting) { - usb_audio_dbg(ep->chip, - "Re-using EP %x in iface %d,%d @%p\n", - ep_num, ep->iface, ep->altsetting, ep); - goto __exit_unlock; - } + ep = snd_usb_get_endpoint(chip, ep_num, + alts->desc.bInterfaceNumber, + alts->desc.bAlternateSetting); + if (ep) { + usb_audio_dbg(ep->chip, "Re-using EP %x in iface %d,%d @%p\n", + ep_num, ep->iface, ep->altsetting, ep); + goto __exit_unlock; } usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n", diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h index d23fa0a8c11b..61487095a766 100644 --- a/sound/usb/endpoint.h +++ b/sound/usb/endpoint.h @@ -5,6 +5,10 @@ #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 iface, + int altsetting); + struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip, struct usb_host_interface *alts, int ep_num, int direction, int type); -- cgit v1.2.3