PPC: dbdma: Allow new commands in RUN state

The DBDMA controller can not change its command stream while it's
actively streaming data, true. But the fact that it's in RUN state
doesn't actually indicate anything. It could just as well be in
WAIT while in RUN. And then it's legal to change commands.

This fixes a real world issue I've encountered with Mac OS X.

Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/hw/misc/macio/mac_dbdma.c b/hw/misc/macio/mac_dbdma.c
index 3b1e97e..7656767 100644 (file)
--- a/hw/misc/macio/mac_dbdma.c
+++ b/hw/misc/macio/mac_dbdma.c
@@ -725,11 +725,11 @@ static void dbdma_write(void *opaque, hwaddr addr,
     DBDMA_DPRINTF("channel 0x%x reg 0x%x\n",
                   (uint32_t)addr >> DBDMA_CHANNEL_SHIFT, reg);
 
-    /* cmdptr cannot be modified if channel is RUN or ACTIVE */
+    /* cmdptr cannot be modified if channel is ACTIVE */
 
-    if (reg == DBDMA_CMDPTR_LO &&
-        (ch->regs[DBDMA_STATUS] & (RUN | ACTIVE)))
+    if (reg == DBDMA_CMDPTR_LO && (ch->regs[DBDMA_STATUS] & ACTIVE)) {
         return;
+    }
 
     ch->regs[reg] = value;