dwc3: gadget: Improve TX FIFO resize functionality

This change considers USB device speed to set max_packet size
instead of provided max_packet value from USB function driver.
It doesn't resize ep0IN TxFIFO, and starts with ep1IN TxFIFO only.

Change-Id: Ifce63f5a8570f79bad1e5d3ae6f5d580c34046b5
Signed-off-by: Mayank Rana <mrana@codeaurora.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index aac030a..99bcfe2 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -180,6 +180,7 @@ int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc)
        int             mdwidth;
        int             num;
        int             num_eps;
+       int             max_packet;
        struct usb_composite_dev *cdev = get_gadget_data(&dwc->gadget);
 
        if (!(cdev && cdev->config) || !dwc->needs_fifo_resize)
@@ -194,14 +195,28 @@ int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc)
        /* MDWIDTH is represented in bits, we need it in bytes */
        mdwidth >>= 3;
 
-       dev_dbg(dwc->dev, "%s: num eps: %d\n", __func__, num_eps);
+       if (dwc->gadget.speed == USB_SPEED_FULL) {
+               max_packet = 64;
+       } else if (dwc->gadget.speed == USB_SPEED_HIGH) {
+               max_packet = 512;
+       } else if (dwc->gadget.speed == USB_SPEED_SUPER) {
+               max_packet = 1024;
+       } else {
+               dev_warn(dwc->dev, "USB speed (%d) is not valid.\n",
+                                               dwc->gadget.speed);
+               return -EINVAL;
+       }
+
+       last_fifo_depth = (dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(0)) & 0xFFFF);
+       dev_dbg(dwc->dev, "%s: num eps:%d max_packet:%d last_fifo_depth:%04x\n",
+                               __func__, num_eps, max_packet, last_fifo_depth);
 
-       for (num = 0; num < num_eps; num++) {
+       /* Don't resize ep0IN TxFIFO, start with ep1IN only. */
+       for (num = 1; num < num_eps; num++) {
                /* bit0 indicates direction; 1 means IN ep */
                struct dwc3_ep  *dep = dwc->eps[(num << 1) | 1];
                int             mult = 1;
                int             tmp;
-               int             max_packet = 1024;
 
                if (!(dep->flags & DWC3_EP_ENABLED)) {
                        dev_warn(dwc->dev, "ep%dIn not enabled", num);
@@ -213,18 +228,8 @@ int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc)
                                usb_endpoint_xfer_bulk(dep->endpoint.desc))
                                || usb_endpoint_xfer_isoc(dep->endpoint.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 (burst only) 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 = mult * (max_packet + mdwidth);
 resize_fifo:
                tmp += mdwidth;