On Fri, 08 Apr 2016 19:52:02 +0200, Daniel Mack wrote:
miniDSP USBStreamer UAC2 devices send clock validity changes with the control field set to zero. The current interrupt handler ignores all packets if the control field does not match the mixer element's, but it really should only do that in case that field is needed to distinguish multiple elements with the same ID.
This patch implements a logic that lets notifications packets pass if the element ID is unique for a given device.
Signed-off-by: Daniel Mack daniel@zonque.org
sound/usb/mixer.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 973274b..aa6f16e 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -2371,6 +2371,7 @@ static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer, __u8 unitid = (index >> 8) & 0xff; __u8 control = (value >> 8) & 0xff; __u8 channel = value & 0xff;
unsigned int count = 0;
if (channel >= MAX_CHANNELS) { usb_audio_dbg(mixer->chip,
@@ -2379,6 +2380,12 @@ static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer, return; }
- for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem)
count++;- if (count == 0)
return;- for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem) { struct usb_mixer_elem_info *info;
@@ -2386,7 +2393,7 @@ static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer, continue;
info = (struct usb_mixer_elem_info *)list;
if (info->control != control)
if (count > 1 && info->control != control) continue;
Just for checking count=0 and count=1, we need no loop to count beforehand. if (info->control != control && (list != mixer->id_elems[unit] || list->list_next_id_elem)) continue;
But, this doesn't look better and is more harder to understand, so I'm not willing to sell it :)
thanks,
Takashi