[0/3] usb: dwc3: gadget: Improve isoc starting mechanism

Message

Thinh Nguyen March 13, 2020, 2:18 a.m. UTC

Currently we use the "retry" method to issue START_TRANSFER command multiple
times, each with a next interval. There's been report that 5 number of retries
may not be enough. See https://lkml.org/lkml/2019/11/11/535

We could increase the number of retries. However, that also may not be enough
depending on different system latency. It is not often that the latency is
higher than 5 isoc intervals. If it goes beyond 5 intervals, let's restart the
whole process again.



Thinh Nguyen (3):
  usb: dwc3: gadget: Properly handle failed kick_transfer
  ute: dwc3: gadget: Store resource index of start cmd
  usb: dwc3: gadget: Issue END_TRANSFER to retry isoc transfer

 drivers/usb/dwc3/gadget.c | 69 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 57 insertions(+), 12 deletions(-)