[Qemu-devel] [5295] Add comment to windows SCSI hack.

[Paul Brook]

Revision: 5295
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5295
Author:   pbrook
Date:     2008-09-22 16:30:29 +0000 (Mon, 22 Sep 2008)

Log Message:
-----------
Add comment to windows SCSI hack.

Modified Paths:
--------------
    trunk/hw/lsi53c895a.c

Modified: trunk/hw/lsi53c895a.c
===================================================================
--- trunk/hw/lsi53c895a.c       2008-09-22 16:29:18 UTC (rev 5294)
+++ trunk/hw/lsi53c895a.c       2008-09-22 16:30:29 UTC (rev 5295)
@@ -1199,6 +1199,11 @@
         }
     }
     if (insn_processed > 10000 && !s->waiting) {
+        /* Some windows drivers make the device spin waiting for a memory
+           location to change.  If we have been executed a lot of code then
+           assume this is the case and force an unexpected device disconnect.
+           This is apparently sufficient to beat the drivers into submission.
+         */
         if (!(s->sien0 & LSI_SIST0_UDC))
             fprintf(stderr, "inf. loop with UDC masked\n");
         lsi_script_scsi_interrupt(s, LSI_SIST0_UDC, 0);