From 2e81c36a00d0eb8ce72faaaec1a1d865617374ae Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Thu, 2 Feb 2012 13:01:12 +0200 Subject: [PATCH] usb: dwc3: gadget: allocate 3 packets for bulk and isoc endpoints Those transfer types are generally high bandwidth, so we want to optimize transfers with those endpoints. For that, databook suggests allocating 3 * wMaxPacketSize of FIFO. Let's do that. Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 1f64e7c1c34f..c30ab6da3d0e 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -172,6 +172,7 @@ int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc) for (num = 0; num < DWC3_ENDPOINTS_NUM; num++) { struct dwc3_ep *dep = dwc->eps[num]; int fifo_number = dep->number >> 1; + int mult = 1; int tmp; if (!(dep->number & 1)) @@ -180,11 +181,26 @@ int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc) if (!(dep->flags & DWC3_EP_ENABLED)) continue; - tmp = dep->endpoint.maxpacket; - tmp += mdwidth; + if (usb_endpoint_xfer_bulk(dep->desc) + || usb_endpoint_xfer_isoc(dep->desc)) + mult = 3; + + /* + * REVISIT: the following assumes we will always have enough + * space available on the FIFO RAM for all possible use cases. + * Make sure that's true somehow and change FIFO allocation + * accordingly. + * + * If we have Bulk or Isochronous endpoints, we want + * them to be able to be very, very fast. So we're giving + * those endpoints a fifo_size which is enough for 3 full + * packets + */ + tmp = mult * (dep->endpoint.maxpacket + mdwidth); tmp += mdwidth; fifo_size = DIV_ROUND_UP(tmp, mdwidth); + fifo_size |= (last_fifo_depth << 16); dev_vdbg(dwc->dev, "%s: Fifo Addr %04x Size %d\n", -- 2.20.1