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usb: dwc3: gadget: allocate 3 packets for bulk and isoc endpoints

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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 <balbi@ti.com>
This commit is contained in:
Felipe Balbi 2012-02-02 13:01:12 +02:00
parent d70d84423c
commit 2e81c36a00
1 changed files with 18 additions and 2 deletions
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20
drivers/usb/dwc3/gadget.c
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@ -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",