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| author | Takashi Iwai <tiwai@suse.de> | 2018-05-02 09:36:28 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-05-02 16:02:33 +0200 |
| commit | b099b9693d23d035c77c218508e083484ff63024 (patch) | |
| tree | e5146fb1601205061cf55e0f82d01cac5c513e47 | |
| parent | 964af639ad699404cbe36d0c1fc85970700e6107 (diff) | |
| download | linux-stable-b099b9693d23d035c77c218508e083484ff63024.tar.gz linux-stable-b099b9693d23d035c77c218508e083484ff63024.tar.bz2 linux-stable-b099b9693d23d035c77c218508e083484ff63024.zip | |
ALSA: usb-audio: Avoid superfluous usb_set_interface() calls
This is a preliminary change for the upcoming quirk implementation.
Currently USB-audio driver tries to call usb_set_interface() whenever
the format change with interface/altset modification happens. In this
patch, the check is replaced with the comparison of cur_altsetting and
the targeted altsetting pointer, so that the driver may skip the
unnecessary function calls.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/usb/pcm.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index ad39b3cca247..ae7d8a0a0a0a 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -499,7 +499,7 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt) iface = usb_ifnum_to_if(dev, fmt->iface); if (WARN_ON(!iface)) return -EINVAL; - alts = &iface->altsetting[fmt->altset_idx]; + alts = usb_altnum_to_altsetting(iface, fmt->altsetting); altsd = get_iface_desc(alts); if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting)) return -EINVAL; @@ -521,9 +521,7 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt) } /* set interface */ - if (subs->interface != fmt->iface || - subs->altset_idx != fmt->altset_idx) { - + if (iface->cur_altsetting != alts) { err = snd_usb_select_mode_quirk(subs, fmt); if (err < 0) return -EIO; @@ -537,12 +535,11 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt) } dev_dbg(&dev->dev, "setting usb interface %d:%d\n", fmt->iface, fmt->altsetting); - subs->interface = fmt->iface; - subs->altset_idx = fmt->altset_idx; - snd_usb_set_interface_quirk(dev); } + subs->interface = fmt->iface; + subs->altset_idx = fmt->altset_idx; subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip, alts, fmt->endpoint, subs->direction, SND_USB_ENDPOINT_TYPE_DATA); |