Changeset 46499 in vbox for trunk/src/VBox/Devices

Timestamp:

Jun 11, 2013 3:54:48 PM (12 years ago)

Author:

vboxsync

Message:

DevDMA: Set TC status bit on transfer completion.

File:

• trunk/src/VBox/Devices/PC/DevDMA.cpp (modified) (2 diffs)

trunk/src/VBox/Devices/PC/DevDMA.cpp

@@ -170 +170 @@
     CTL_W_CLRMASK,  /* Clear all DRQ mask bits. */
     CTL_W_MASK      /* Write all DRQ mask bits. */
+};
+
+/* DMA transfer modes. */
+enum {
+    DMODE_DEMAND,   /* Demand transfer mode. */
+    DMODE_SINGLE,   /* Single transfer mode. */
+    DMODE_BLOCK,    /* Block transfer mode. */
+    DMODE_CASCADE   /* Cascade mode. */
 };
 
@@ -541 +549 @@
     /* Addresses and counts are shifted for 16-bit channels. */
     start_cnt = ch->u16CurCount << dc->is16bit;
+    /* NB: The device is responsible for examining the DMA mode and not
+     * transferring more than it should if auto-init is not in use.
+     */
     end_cnt = ch->pfnXferHandler(pThis->pDevIns, ch->pvUser, (ctlidx * 4) + chidx,
                                  start_cnt, (ch->u16BaseCount + 1) << dc->is16bit);
     ch->u16CurCount = end_cnt >> dc->is16bit;
+    /* Set the TC (Terminal Count) bit if transfer was completed. */
+    if (ch->u16CurCount == ch->u16BaseCount + 1)
+        switch (opmode) 
+        {
+        case DMODE_DEMAND:
+        case DMODE_SINGLE:
+        case DMODE_BLOCK:
+            dc->u8Status |= RT_BIT(chidx);
+            Log3(("TC set for DMA channel %d\n", (ctlidx * 4) + chidx));
+            break;
+        default:
+            break;
+        }
     Log3(("DMA position %d, size %d\n", end_cnt, (ch->u16BaseCount + 1) << dc->is16bit));
 }