From: Andreas Pape <apape@xxxxxxxxxxxxxx> since commit 57e6dae1087bbaa6b33d3dd8a8e90b63888939a3 the expected packetsize is always limited to nominal + 25%. It was discovered, that some devices have a much higher jitter in used packetsizes than 25% which would result in BABBLE condition and dropping of packets. A better solution is so assume the jitter to be the nominal packetsize: -one nearly empty packet followed by a almost double sized one. Signed-off-by: Andreas Pape <apape@xxxxxxxxxxxxxx> Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx> --- sound/usb/endpoint.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index c470251..2f592dd 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -632,8 +632,8 @@ static int data_ep_set_params(struct snd_usb_endpoint *ep, ep->stride = frame_bits >> 3; ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0; - /* assume max. frequency is 25% higher than nominal */ - ep->freqmax = ep->freqn + (ep->freqn >> 2); + /* assume max. frequency is double than nominal */ + ep->freqmax = ep->freqn * 2; /* Round up freqmax to nearest integer in order to calculate maximum * packet size, which must represent a whole number of frames. * This is accomplished by adding 0x0.ffff before converting the -- 2.9.3 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
