Changeset 2842 in vbox for trunk/src/VBox/Devices

Timestamp:

May 24, 2007 3:33:44 PM (18 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

21479

Message:

Mark drive as ready immediately after a completed PIO read. This
addresses the Linux guest PIO read problem, see #1571.

File:

• trunk/src/VBox/Devices/Storage/DevATA.cpp (modified) (3 diffs)

trunk/src/VBox/Devices/Storage/DevATA.cpp

@@ -3617 +3617 @@
     }
 
-    ataUnsetStatus(s, ATA_STAT_READY | ATA_STAT_DRQ);
-    ataSetStatus(s, ATA_STAT_BUSY);
-
-    Log2(("%s: Ctl#%d: message to async I/O thread, continuing PIO transfer\n", __FUNCTION__, ATACONTROLLER_IDX(pCtl)));
-    ataAsyncIOPutRequest(pCtl, &ataPIORequest);
+    if (s->uTxDir == PDMBLOCKTXDIR_TO_DEVICE || s->iSourceSink != ATAFN_SS_NULL)
+    {
+        /* Need to continue the transfer in the async I/O thread. This is
+         * the case for write operations or generally for not yet finished
+         * transfers (some data might need to be read). */
+        ataUnsetStatus(s, ATA_STAT_READY | ATA_STAT_DRQ);
+        ataSetStatus(s, ATA_STAT_BUSY);
+
+        Log2(("%s: Ctl#%d: message to async I/O thread, continuing PIO transfer\n", __FUNCTION__, ATACONTROLLER_IDX(pCtl)));
+        ataAsyncIOPutRequest(pCtl, &ataPIORequest);
+    }
+    else
+    {
+        /* Everything finished, mark device as ready. */
+        ataUnsetStatus(s, ATA_STAT_DRQ);
+
+        Log2(("%s: Ctl#%d: skipping message to async I/O thread, ending PIO transfer\n", __FUNCTION__, ATACONTROLLER_IDX(pCtl)));
+        ataPIOTransferStop(s);
+    }
 }
 
@@ -4168 +4182 @@
                             ataSetIRQ(s);
 
-                        pCtl->uAsyncIOState = ATA_AIO_PIO;
+                        if (s->uTxDir == PDMBLOCKTXDIR_TO_DEVICE || s->iSourceSink != ATAFN_SS_NULL)
+                        {
+                            /* Write operations and not yet finished transfers
+                             * must be completed in the async I/O thread. */
+                            pCtl->uAsyncIOState = ATA_AIO_PIO;
+                        }
+                        else
+                        {
+                            /* Finished read operation can be handled inline
+                             * in the end of PIO transfer handling code. Linux
+                             * depends on this, as it waits only briefly for
+                             * devices to become ready after incoming data
+                             * transfer. Cannot find anything in the ATA spec
+                             * that backs this assumption, but as all kernels
+                             * are affected (though most of the time it does
+                             * not cause any harm) this must work. */
+                            pCtl->uAsyncIOState = ATA_AIO_NEW;
+                        }
                     }
                     else
@@ -4279 +4310 @@
                     ataSetIRQ(s);
 
-                    pCtl->uAsyncIOState = ATA_AIO_PIO;
+                    if (s->uTxDir == PDMBLOCKTXDIR_TO_DEVICE || s->iSourceSink != ATAFN_SS_NULL)
+                    {
+                        /* Write operations and not yet finished transfers
+                         * must be completed in the async I/O thread. */
+                        pCtl->uAsyncIOState = ATA_AIO_PIO;
+                    }
+                    else
+                    {
+                        /* Finished read operation can be handled inline
+                         * in the end of PIO transfer handling code. Linux
+                         * depends on this, as it waits only briefly for
+                         * devices to become ready after incoming data
+                         * transfer. Cannot find anything in the ATA spec
+                         * that backs this assumption, but as all kernels
+                         * are affected (though most of the time it does
+                         * not cause any harm) this must work. */
+                        pCtl->uAsyncIOState = ATA_AIO_NEW;
+                    }
                 }
                 else