xhci: rip out background transfer code

original xhci code (the one which used libusb directly) used to use
'background transfers' for iso streams.  In upstream qemu the iso
stream buffering is handled by usb-host & usb-redir, so we will
never ever need this.  It has been left in as reference, but is dead
code anyway.  Rip it out.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/usb/hcd-xhci.c

@@ -45,8 +45,6 @@
 #define MAXPORTS (USB2_PORTS+USB3_PORTS)
 
 #define TD_QUEUE 24
-#define BG_XFERS 8
-#define BG_PKTS 8
 
 /* Very pessimistic, let's hope it's enough for all cases */
 #define EV_QUEUE (((3*TD_QUEUE)+16)*MAXSLOTS)
@@ -311,13 +309,11 @@ typedef struct XHCITransfer {
     bool running_retry;
     bool cancelled;
     bool complete;
-    bool backgrounded;
     unsigned int iso_pkts;
     unsigned int slotid;
     unsigned int epid;
     bool in_xfer;
     bool iso_xfer;
-    bool bg_xfer;
 
     unsigned int trb_count;
     unsigned int trb_alloced;
@@ -340,14 +336,9 @@ typedef struct XHCIEPContext {
     unsigned int comp_xfer;
     XHCITransfer transfers[TD_QUEUE];
     XHCITransfer *retry;
-    bool bg_running;
-    bool bg_updating;
-    unsigned int next_bg;
-    XHCITransfer bg_transfers[BG_XFERS];
     EPType type;
     dma_addr_t pctx;
     unsigned int max_psize;
-    bool has_bg;
     uint32_t state;
 } XHCIEPContext;
 
@@ -866,10 +857,6 @@ static TRBCCode xhci_enable_ep(XHCIState *xhci, unsigned int slotid,
     epctx->pctx = pctx;
     epctx->max_psize = ctx[1]>>16;
     epctx->max_psize *= 1+((ctx[1]>>8)&0xff);
-    epctx->has_bg = false;
-    if (epctx->type == ET_ISO_IN) {
-        epctx->has_bg = true;
-    }
     DPRINTF("xhci: endpoint %d.%d max transaction (burst) size is %d\n",
             epid/2, epid%2, epctx->max_psize);
     for (i = 0; i < ARRAY_SIZE(epctx->transfers); i++) {
@@ -916,9 +903,6 @@ static int xhci_ep_nuke_xfers(XHCIState *xhci, unsigned int slotid,
             t->running_retry = 0;
             epctx->retry = NULL;
         }
-        if (t->backgrounded) {
-            t->backgrounded = 0;
-        }
         if (t->trbs) {
             g_free(t->trbs);
         }
@@ -932,25 +916,6 @@ static int xhci_ep_nuke_xfers(XHCIState *xhci, unsigned int slotid,
         t->data_length = t->data_alloced = 0;
         xferi = (xferi + 1) % TD_QUEUE;
     }
-    if (epctx->has_bg) {
-        xferi = epctx->next_bg;
-        for (i = 0; i < BG_XFERS; i++) {
-            XHCITransfer *t = &epctx->bg_transfers[xferi];
-            if (t->running_async) {
-                usb_cancel_packet(&t->packet);
-                t->running_async = 0;
-                t->cancelled = 1;
-                DPRINTF("xhci: cancelling bg transfer %d, waiting for it to complete...\n", i);
-                killed++;
-            }
-            if (t->data) {
-                g_free(t->data);
-            }
-
-            t->data = NULL;
-            xferi = (xferi + 1) % BG_XFERS;
-        }
-    }
     return killed;
 }
 
@@ -1231,160 +1196,6 @@ static void xhci_stall_ep(XHCITransfer *xfer)
 static int xhci_submit(XHCIState *xhci, XHCITransfer *xfer,
                        XHCIEPContext *epctx);
 
-static void xhci_bg_update(XHCIState *xhci, XHCIEPContext *epctx)
-{
-    if (epctx->bg_updating) {
-        return;
-    }
-    DPRINTF("xhci_bg_update(%p, %p)\n", xhci, epctx);
-    assert(epctx->has_bg);
-    DPRINTF("xhci: fg=%d bg=%d\n", epctx->comp_xfer, epctx->next_bg);
-    epctx->bg_updating = 1;
-    while (epctx->transfers[epctx->comp_xfer].backgrounded &&
-           epctx->bg_transfers[epctx->next_bg].complete) {
-        XHCITransfer *fg = &epctx->transfers[epctx->comp_xfer];
-        XHCITransfer *bg = &epctx->bg_transfers[epctx->next_bg];
-#if 0
-        DPRINTF("xhci: completing fg %d from bg %d.%d (stat: %d)\n",
-                epctx->comp_xfer, epctx->next_bg, bg->cur_pkt,
-                bg->usbxfer->iso_packet_desc[bg->cur_pkt].status
-               );
-#endif
-        assert(epctx->type == ET_ISO_IN);
-        assert(bg->iso_xfer);
-        assert(bg->in_xfer);
-        uint8_t *p = bg->data + bg->cur_pkt * bg->pktsize;
-#if 0
-        int len = bg->usbxfer->iso_packet_desc[bg->cur_pkt].actual_length;
-        fg->status = libusb_to_ccode(bg->usbxfer->iso_packet_desc[bg->cur_pkt].status);
-#else
-        int len = 0;
-        FIXME();
-#endif
-        fg->complete = 1;
-        fg->backgrounded = 0;
-
-        if (fg->status == CC_STALL_ERROR) {
-            xhci_stall_ep(fg);
-        }
-
-        xhci_xfer_data(fg, p, len, 1, 0, 1);
-
-        epctx->comp_xfer++;
-        if (epctx->comp_xfer == TD_QUEUE) {
-            epctx->comp_xfer = 0;
-        }
-        DPRINTF("next fg xfer: %d\n", epctx->comp_xfer);
-        bg->cur_pkt++;
-        if (bg->cur_pkt == bg->pkts) {
-            bg->complete = 0;
-            if (xhci_submit(xhci, bg, epctx) < 0) {
-                fprintf(stderr, "xhci: bg resubmit failed\n");
-            }
-            epctx->next_bg++;
-            if (epctx->next_bg == BG_XFERS) {
-                epctx->next_bg = 0;
-            }
-            DPRINTF("next bg xfer: %d\n", epctx->next_bg);
-
-        xhci_kick_ep(xhci, fg->slotid, fg->epid);
-        }
-    }
-    epctx->bg_updating = 0;
-}
-
-#if 0
-static void xhci_xfer_cb(struct libusb_transfer *transfer)
-{
-    XHCIState *xhci;
-    XHCITransfer *xfer;
-
-    xfer = (XHCITransfer *)transfer->user_data;
-    xhci = xfer->xhci;
-
-    DPRINTF("xhci_xfer_cb(slot=%d, ep=%d, status=%d)\n", xfer->slotid,
-            xfer->epid, transfer->status);
-
-    assert(xfer->slotid >= 1 && xfer->slotid <= MAXSLOTS);
-    assert(xfer->epid >= 1 && xfer->epid <= 31);
-
-    if (xfer->cancelled) {
-        DPRINTF("xhci: transfer cancelled, not reporting anything\n");
-        xfer->running = 0;
-        return;
-    }
-
-    XHCIEPContext *epctx;
-    XHCISlot *slot;
-    slot = &xhci->slots[xfer->slotid-1];
-    assert(slot->eps[xfer->epid-1]);
-    epctx = slot->eps[xfer->epid-1];
-
-    if (xfer->bg_xfer) {
-        DPRINTF("xhci: background transfer, updating\n");
-        xfer->complete = 1;
-        xfer->running = 0;
-        xhci_bg_update(xhci, epctx);
-        return;
-    }
-
-    if (xfer->iso_xfer) {
-        transfer->status = transfer->iso_packet_desc[0].status;
-        transfer->actual_length = transfer->iso_packet_desc[0].actual_length;
-    }
-
-    xfer->status = libusb_to_ccode(transfer->status);
-
-    xfer->complete = 1;
-    xfer->running = 0;
-
-    if (transfer->status == LIBUSB_TRANSFER_STALL)
-        xhci_stall_ep(xhci, epctx, xfer);
-
-    DPRINTF("xhci: transfer actual length = %d\n", transfer->actual_length);
-
-    if (xfer->in_xfer) {
-        if (xfer->epid == 1) {
-            xhci_xfer_data(xhci, xfer, xfer->data + 8,
-                           transfer->actual_length, 1, 0, 1);
-        } else {
-            xhci_xfer_data(xhci, xfer, xfer->data,
-                           transfer->actual_length, 1, 0, 1);
-        }
-    } else {
-        xhci_xfer_data(xhci, xfer, NULL, transfer->actual_length, 0, 0, 1);
-    }
-
-    xhci_kick_ep(xhci, xfer->slotid, xfer->epid);
-}
-
-static int xhci_hle_control(XHCIState *xhci, XHCITransfer *xfer,
-                            uint8_t bmRequestType, uint8_t bRequest,
-                            uint16_t wValue, uint16_t wIndex, uint16_t wLength)
-{
-    uint16_t type_req = (bmRequestType << 8) | bRequest;
-
-    switch (type_req) {
-        case 0x0000 | USB_REQ_SET_CONFIGURATION:
-            DPRINTF("xhci: HLE switch configuration\n");
-            return xhci_switch_config(xhci, xfer->slotid, wValue) == 0;
-        case 0x0100 | USB_REQ_SET_INTERFACE:
-            DPRINTF("xhci: HLE set interface altsetting\n");
-            return xhci_set_iface_alt(xhci, xfer->slotid, wIndex, wValue) == 0;
-        case 0x0200 | USB_REQ_CLEAR_FEATURE:
-            if (wValue == 0) { // endpoint halt
-                DPRINTF("xhci: HLE clear halt\n");
-                return xhci_clear_halt(xhci, xfer->slotid, wIndex);
-            }
-        case 0x0000 | USB_REQ_SET_ADDRESS:
-            fprintf(stderr, "xhci: warn: illegal SET_ADDRESS request\n");
-            return 0;
-        default:
-            return 0;
-    }
-}
-#endif
-
 static int xhci_setup_packet(XHCITransfer *xfer, USBDevice *dev)
 {
     USBEndpoint *ep;
@@ -1559,9 +1370,7 @@ static int xhci_submit(XHCIState *xhci, XHCITransfer *xfer, XHCIEPContext *epctx
         xfer->data_alloced = xfer->data_length;
     }
     if (epctx->type == ET_ISO_IN || epctx->type == ET_ISO_OUT) {
-        if (!xfer->bg_xfer) {
-            xfer->pkts = 1;
-        }
+        xfer->pkts = 1;
     } else {
         xfer->pkts = 0;
     }
@@ -1620,32 +1429,8 @@ static int xhci_fire_transfer(XHCIState *xhci, XHCITransfer *xfer, XHCIEPContext
 
     trace_usb_xhci_xfer_start(xfer, xfer->slotid, xfer->epid, length);
 
-    if (!epctx->has_bg) {
-        xfer->data_length = length;
-        xfer->backgrounded = 0;
-        return xhci_submit(xhci, xfer, epctx);
-    } else {
-        if (!epctx->bg_running) {
-            for (i = 0; i < BG_XFERS; i++) {
-                XHCITransfer *t = &epctx->bg_transfers[i];
-                t->xhci = xhci;
-                t->epid = xfer->epid;
-                t->slotid = xfer->slotid;
-                t->pkts = BG_PKTS;
-                t->pktsize = epctx->max_psize;
-                t->data_length = t->pkts * t->pktsize;
-                t->bg_xfer = 1;
-                if (xhci_submit(xhci, t, epctx) < 0) {
-                    fprintf(stderr, "xhci: bg submit failed\n");
-                    return -1;
-                }
-            }
-            epctx->bg_running = 1;
-        }
-        xfer->backgrounded = 1;
-        xhci_bg_update(xhci, epctx);
-        return 0;
-    }
+    xfer->data_length = length;
+    return xhci_submit(xhci, xfer, epctx);
 }
 
 static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid, unsigned int epid)
@@ -1695,7 +1480,7 @@ static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid, unsigned int epid
 
     while (1) {
         XHCITransfer *xfer = &epctx->transfers[epctx->next_xfer];
-        if (xfer->running_async || xfer->running_retry || xfer->backgrounded) {
+        if (xfer->running_async || xfer->running_retry) {
             break;
         }
         length = xhci_ring_chain_length(xhci, &epctx->ring);