tree 749a58c5972b72aec1a78c765f2f9cf4b3e1a776
parent 1e2e3fe480064ca33186e5a923beaa160efed35d
author Andreas Pape <apape@de.adit-jv.com> 1481003174 +0900
committer Takashi Iwai <tiwai@suse.de> 1481028959 +0100

ALSA: usb-audio: more tolerant packetsize

since commit 57e6dae1087b ("ALSA: usb-audio: do not trust too-big
wMaxPacketSize values"), the expected packetsize is always limited
to nominal + 25%. It was discovered, that some devices (Android audio
accessory) 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 150% sized one.

V2: changed to assume max frequency is +50 of nominal packetsize.

Signed-off-by: Andreas Pape <apape@de.adit-jv.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>