[Qemu-devel] [PATCH 4/4] uhci: Don't retry on error

[Hans de Goede <hdegoede@redhat.com>]

Since we are either dealing with emulated devices, where retrying is
not going to help, or with redirected devices where the host OS will
have already retried, don't bother retrying on failed transfers.

Also move some common/indentical code out of all the error cases
into the generic error path.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 hw/usb/hcd-uhci.c | 62 +++++++++++++++++--------------------------------------
 1 file changed, 19 insertions(+), 43 deletions(-)

diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index 1e0920e..400a337 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -696,10 +696,6 @@ static USBDevice *uhci_find_device(UHCIState *s, uint8_t addr)
 static void uhci_async_complete(USBPort *port, USBPacket *packet);
 static void uhci_process_frame(UHCIState *s);
 
-/* return -1 if fatal error (frame must be stopped)
-          0 if TD successful
-          1 if TD unsuccessful or inactive
-*/
 static int uhci_complete_td(UHCIState *s, UHCI_TD *td, UHCIAsync *async, uint32_t *int_mask)
 {
     int len = 0, max_len, err;
@@ -741,60 +737,40 @@ static int uhci_complete_td(UHCIState *s, UHCI_TD *td, UHCIAsync *async, uint32_
 
 out:
     switch (async->packet.status) {
+    case USB_RET_NAK:
+        td->ctrl |= TD_CTRL_NAK;
+        return TD_RESULT_NEXT_QH;
+
     case USB_RET_STALL:
         td->ctrl |= TD_CTRL_STALL;
-        td->ctrl &= ~TD_CTRL_ACTIVE;
-        s->status |= UHCI_STS_USBERR;
-        if (td->ctrl & TD_CTRL_IOC) {
-            *int_mask |= 0x01;
-        }
-        uhci_update_irq(s);
         trace_usb_uhci_packet_complete_stall(async->queue->token, async->td);
-        return TD_RESULT_NEXT_QH;
+        err = TD_RESULT_NEXT_QH;
+        break;
 
     case USB_RET_BABBLE:
         td->ctrl |= TD_CTRL_BABBLE | TD_CTRL_STALL;
-        td->ctrl &= ~TD_CTRL_ACTIVE;
-        s->status |= UHCI_STS_USBERR;
-        if (td->ctrl & TD_CTRL_IOC) {
-            *int_mask |= 0x01;
-        }
-        uhci_update_irq(s);
         /* frame interrupted */
         trace_usb_uhci_packet_complete_babble(async->queue->token, async->td);
-        return TD_RESULT_STOP_FRAME;
-
-    case USB_RET_NAK:
-        td->ctrl |= TD_CTRL_NAK;
-        if (pid == USB_TOKEN_SETUP)
-            break;
-        return TD_RESULT_NEXT_QH;
+        err = TD_RESULT_STOP_FRAME;
+        break;
 
     case USB_RET_IOERROR:
     case USB_RET_NODEV:
     default:
-	break;
+        td->ctrl |= TD_CTRL_TIMEOUT;
+        td->ctrl &= ~(3 << TD_CTRL_ERROR_SHIFT);
+        trace_usb_uhci_packet_complete_error(async->queue->token, async->td);
+        err = TD_RESULT_NEXT_QH;
+        break;
     }
 
-    /* Retry the TD if error count is not zero */
-
-    td->ctrl |= TD_CTRL_TIMEOUT;
-    err = (td->ctrl >> TD_CTRL_ERROR_SHIFT) & 3;
-    if (err != 0) {
-        err--;
-        if (err == 0) {
-            td->ctrl &= ~TD_CTRL_ACTIVE;
-            s->status |= UHCI_STS_USBERR;
-            if (td->ctrl & TD_CTRL_IOC)
-                *int_mask |= 0x01;
-            uhci_update_irq(s);
-            trace_usb_uhci_packet_complete_error(async->queue->token,
-                                                 async->td);
-        }
+    td->ctrl &= ~TD_CTRL_ACTIVE;
+    s->status |= UHCI_STS_USBERR;
+    if (td->ctrl & TD_CTRL_IOC) {
+        *int_mask |= 0x01;
     }
-    td->ctrl = (td->ctrl & ~(3 << TD_CTRL_ERROR_SHIFT)) |
-        (err << TD_CTRL_ERROR_SHIFT);
-    return TD_RESULT_NEXT_QH;
+    uhci_update_irq(s);
+    return err;
 }
 
 static int uhci_handle_td(UHCIState *s, uint32_t addr, UHCI_TD *td,
-- 
1.7.12.1