Commit f1d6826c authored Apr 21, 2017 by Roger Quadros Committed by Felipe Balbi May 16, 2017

usb: dwc3: gadget: Fix ISO transfer performance



Commit 08a36b54 ("usb: dwc3: gadget: simplify __dwc3_gadget_ep_queue()")
caused a small change in the way ISO transfer is handled in the case
when XferInProgress event happens on Isoc EP with an active transfer.
This caused a performance degradation of 50%. e.g. using g_webcam on DUT
and luvcview on host the video frame rate dropped from 16fps to 8fps
@high-speed.

Make the ISO transfer handling equivalent to that prior to that commit
to get back the original ISO performance numbers.

Fixes: 08a36b54 ("usb: dwc3: gadget: simplify __dwc3_gadget_ep_queue()")
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

parent 68217959

drivers/usb/dwc3/gadget.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -1261,14 +1261,24 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep dep, struct dwc3_request req)
		__dwc3_gadget_start_isoc(dwc, dep, cur_uf);
		dep->flags &= ~DWC3_EP_PENDING_REQUEST;
		}
		}
		return 0;
		}

		if ((dep->flags & DWC3_EP_BUSY) &&
		!(dep->flags & DWC3_EP_MISSED_ISOC)) {
		WARN_ON_ONCE(!dep->resource_index);
		ret = __dwc3_gadget_kick_transfer(dep,
		dep->resource_index);
		}

		goto out;
		}

		if (!dwc3_calc_trbs_left(dep))
		return 0;

		ret = __dwc3_gadget_kick_transfer(dep, 0);
		out:
		if (ret == -EBUSY)
		ret = 0;