[Qemu-devel] [PATCH] fix use of host serial port

["David S. Ahern" <daahern@cisco.com>]

I need to drive this to ground. Can I get this applied?

Thanks,
davd


The following patch fixes use of a host serial port.

My original post on the problem is:
http://marc.info/?l=kvm&m=122995568009533&w=2

Michael Tokarev (mjt@tls.msk.ru) dug into the where the code was
failing: http://marc.info/?l=kvm&m=123300124703645&w=2

and further suggested a solution on which this patch is based.

The changed has been acked by Stefano Stabellini.

Signed-off-by: David Ahern <daahern@cisco.com>


Index: trunk/qemu-char.c
===================================================================
--- trunk/qemu-char.c   (revision 6545)
+++ trunk/qemu-char.c   (working copy)
@@ -1047,17 +1047,17 @@
             int *targ = (int *)arg;
             ioctl(s->fd_in, TIOCMGET, &sarg);
             *targ = 0;
-            if (sarg | TIOCM_CTS)
+            if (sarg & TIOCM_CTS)
                 *targ |= CHR_TIOCM_CTS;
-            if (sarg | TIOCM_CAR)
+            if (sarg & TIOCM_CAR)
                 *targ |= CHR_TIOCM_CAR;
-            if (sarg | TIOCM_DSR)
+            if (sarg & TIOCM_DSR)
                 *targ |= CHR_TIOCM_DSR;
-            if (sarg | TIOCM_RI)
+            if (sarg & TIOCM_RI)
                 *targ |= CHR_TIOCM_RI;
-            if (sarg | TIOCM_DTR)
+            if (sarg & TIOCM_DTR)
                 *targ |= CHR_TIOCM_DTR;
-            if (sarg | TIOCM_RTS)
+            if (sarg & TIOCM_RTS)
                 *targ |= CHR_TIOCM_RTS;
         }
         break;
@@ -1065,9 +1065,20 @@
         {
             int sarg = *(int *)arg;
             int targ = 0;
-            if (sarg | CHR_TIOCM_DTR)
+            ioctl(s->fd_in, TIOCMGET, &targ);
+            targ &= ~(CHR_TIOCM_CTS | CHR_TIOCM_CAR | CHR_TIOCM_DSR
+                     | CHR_TIOCM_RI | CHR_TIOCM_DTR | CHR_TIOCM_RTS);
+            if (sarg & CHR_TIOCM_CTS)
+                targ |= TIOCM_CTS;
+            if (sarg & CHR_TIOCM_CAR)
+                targ |= TIOCM_CAR;
+            if (sarg & CHR_TIOCM_DSR)
+                targ |= TIOCM_DSR;
+            if (sarg & CHR_TIOCM_RI)
+                targ |= TIOCM_RI;
+            if (sarg & CHR_TIOCM_DTR)
                 targ |= TIOCM_DTR;
-            if (sarg | CHR_TIOCM_RTS)
+            if (sarg & CHR_TIOCM_RTS)
                 targ |= TIOCM_RTS;
             ioctl(s->fd_in, TIOCMSET, &targ);
         }