usb: split packet result into actual_length + status

Since with the ehci and xhci controllers a single packet can be larger
then maxpacketsize, it is possible for the result of a single packet
to be both having transferred some data as well as the transfer to have
an error.

An example would be an input transfer from a bulk endpoint successfully
receiving 1 or more maxpacketsize packets from the device, followed
by a packet signalling halt.

While already touching all the devices and controllers handle_packet /
handle_data / handle_control code, also change the return type of
these functions to void, solely storing the status in the packet. To
make the code paths for regular versus async packet handling more
uniform.

This patch unfortunately is somewhat invasive, since makeing the qemu
usb core deal with this requires changes everywhere. This patch only
prepares the usb core for this, all the hcd / device changes are done
in such a way that there are no functional changes.

This patch has been tested with uhci and ehci hcds, together with usb-audio,
usb-hid and usb-storage devices, as well as with usb-redir redirection
with a wide variety of real devices.

Note that there is usually no need to directly set packet->actual_length
form devices handle_data callback, as that is done by usb_packet_copy()

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 22 insertions, 24 deletions

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 900abf5566..d4a2e0c3ec 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -1388,7 +1388,7 @@ static void xhci_xfer_report(XHCITransfer *xfer)
     XHCIState *xhci = xfer->xhci;
     int i;
 
-    left = xfer->packet.result < 0 ? 0 : xfer->packet.result;
+    left = xfer->packet.status ? 0 : xfer->packet.actual_length;
 
     for (i = 0; i < xfer->trb_count; i++) {
         XHCITRB *trb = &xfer->trbs[i];
@@ -1490,16 +1490,16 @@ static int xhci_setup_packet(XHCITransfer *xfer)
     return 0;
 }
 
-static int xhci_complete_packet(XHCITransfer *xfer, int ret)
+static int xhci_complete_packet(XHCITransfer *xfer)
 {
-    if (ret == USB_RET_ASYNC) {
+    if (xfer->packet.status == USB_RET_ASYNC) {
         trace_usb_xhci_xfer_async(xfer);
         xfer->running_async = 1;
         xfer->running_retry = 0;
         xfer->complete = 0;
         xfer->cancelled = 0;
         return 0;
-    } else if (ret == USB_RET_NAK) {
+    } else if (xfer->packet.status == USB_RET_NAK) {
         trace_usb_xhci_xfer_nak(xfer);
         xfer->running_async = 0;
         xfer->running_retry = 1;
@@ -1513,16 +1513,16 @@ static int xhci_complete_packet(XHCITransfer *xfer, int ret)
         xhci_xfer_unmap(xfer);
     }
 
-    if (ret >= 0) {
-        trace_usb_xhci_xfer_success(xfer, ret);
+    if (xfer->packet.status == USB_RET_SUCCESS) {
+        trace_usb_xhci_xfer_success(xfer, xfer->packet.actual_length);
         xfer->status = CC_SUCCESS;
         xhci_xfer_report(xfer);
         return 0;
     }
 
     /* error */
-    trace_usb_xhci_xfer_error(xfer, ret);
-    switch (ret) {
+    trace_usb_xhci_xfer_error(xfer, xfer->packet.status);
+    switch (xfer->packet.status) {
     case USB_RET_NODEV:
         xfer->status = CC_USB_TRANSACTION_ERROR;
         xhci_xfer_report(xfer);
@@ -1534,7 +1534,8 @@ static int xhci_complete_packet(XHCITransfer *xfer, int ret)
         xhci_stall_ep(xfer);
         break;
     default:
-        fprintf(stderr, "%s: FIXME: ret = %d\n", __FUNCTION__, ret);
+        fprintf(stderr, "%s: FIXME: status = %d\n", __func__,
+                xfer->packet.status);
         FIXME();
     }
     return 0;
@@ -1544,7 +1545,6 @@ static int xhci_fire_ctl_transfer(XHCIState *xhci, XHCITransfer *xfer)
 {
     XHCITRB *trb_setup, *trb_status;
     uint8_t bmRequestType;
-    int ret;
 
     trb_setup = &xfer->trbs[0];
     trb_status = &xfer->trbs[xfer->trb_count-1];
@@ -1587,9 +1587,9 @@ static int xhci_fire_ctl_transfer(XHCIState *xhci, XHCITransfer *xfer)
     }
     xfer->packet.parameter = trb_setup->parameter;
 
-    ret = usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
+    usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
 
-    xhci_complete_packet(xfer, ret);
+    xhci_complete_packet(xfer);
     if (!xfer->running_async && !xfer->running_retry) {
         xhci_kick_ep(xhci, xfer->slotid, xfer->epid);
     }
@@ -1636,7 +1636,6 @@ static void xhci_check_iso_kick(XHCIState *xhci, XHCITransfer *xfer,
 static int xhci_submit(XHCIState *xhci, XHCITransfer *xfer, XHCIEPContext *epctx)
 {
     uint64_t mfindex;
-    int ret;
 
     DPRINTF("xhci_submit(slotid=%d,epid=%d)\n", xfer->slotid, xfer->epid);
 
@@ -1671,9 +1670,9 @@ static int xhci_submit(XHCIState *xhci, XHCITransfer *xfer, XHCIEPContext *epctx
     if (xhci_setup_packet(xfer) < 0) {
         return -1;
     }
-    ret = usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
+    usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
 
-    xhci_complete_packet(xfer, ret);
+    xhci_complete_packet(xfer);
     if (!xfer->running_async && !xfer->running_retry) {
         xhci_kick_ep(xhci, xfer->slotid, xfer->epid);
     }
@@ -1711,7 +1710,6 @@ static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid, unsigned int epid
 
     if (epctx->retry) {
         XHCITransfer *xfer = epctx->retry;
-        int result;
 
         trace_usb_xhci_xfer_retry(xfer);
         assert(xfer->running_retry);
@@ -1725,19 +1723,19 @@ static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid, unsigned int epid
             if (xhci_setup_packet(xfer) < 0) {
                 return;
             }
-            result = usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
-            assert(result != USB_RET_NAK);
-            xhci_complete_packet(xfer, result);
+            usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
+            assert(xfer->packet.status != USB_RET_NAK);
+            xhci_complete_packet(xfer);
         } else {
             /* retry nak'ed transfer */
             if (xhci_setup_packet(xfer) < 0) {
                 return;
             }
-            result = usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
-            if (result == USB_RET_NAK) {
+            usb_handle_packet(xfer->packet.ep->dev, &xfer->packet);
+            if (xfer->packet.status == USB_RET_NAK) {
                 return;
             }
-            xhci_complete_packet(xfer, result);
+            xhci_complete_packet(xfer);
         }
         assert(!xfer->running_retry);
         epctx->retry = NULL;
@@ -2922,11 +2920,11 @@ static void xhci_complete(USBPort *port, USBPacket *packet)
 {
     XHCITransfer *xfer = container_of(packet, XHCITransfer, packet);
 
-    if (packet->result == USB_RET_REMOVE_FROM_QUEUE) {
+    if (packet->status == USB_RET_REMOVE_FROM_QUEUE) {
         xhci_ep_nuke_one_xfer(xfer);
         return;
     }
-    xhci_complete_packet(xfer, packet->result);
+    xhci_complete_packet(xfer);
     xhci_kick_ep(xfer->xhci, xfer->slotid, xfer->epid);
 }