[PATCH 4.9 155/191] ALSA: usb-audio: uac1: Invalidate ctl on interrupt

Sasha Levin
2020-06-29T19:27:00Z

From: Julian Scheel <julian@jusst.de>

[ Upstream commit b2500b584cfd228d67e1e43daf27c8af865b499e ]

When an interrupt occurs, the value of at least one of the belonging
controls should have changed. To make sure they get re-read from device
on the next read, invalidate the cache. This was correctly implemented
for uac2 already, but missing for uac1.

Signed-off-by: Julian Scheel <julian@jusst.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/usb/mixer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 024864ce3f761..60423d2572c7d 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -2397,9 +2397,14 @@ void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
{
struct usb_mixer_elem_list *list;

- for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem)
+ for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem) {
+ struct usb_mixer_elem_info *info =
+ (struct usb_mixer_elem_info *)list;
+ /* invalidate cache, so the value is read from the device */
+ info->cached = 0;
snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
&list->kctl->id);
+ }
}

static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,
--
2.25.1