[PATCH] bcm2835_dma: Fix TD mode

[Rene Stange <rsta2@o2online.de>]

TD (two dimensions) DMA mode did not work, because the xlen variable has
not been re-initialized before each additional ylen run through in
bcm2835_dma_update(). Furthermore ylen has to be increased by one after
reading it from the TXFR_LEN register, because a value of zero has to
result in one run through of the ylen loop. Both issues have been fixed.

Signed-off-by: Rene Stange <rsta2@o2online.de>
---
 hw/dma/bcm2835_dma.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/hw/dma/bcm2835_dma.c b/hw/dma/bcm2835_dma.c
index 1e458d7fba..0881c9506e 100644
--- a/hw/dma/bcm2835_dma.c
+++ b/hw/dma/bcm2835_dma.c
@@ -54,7 +54,7 @@
 static void bcm2835_dma_update(BCM2835DMAState *s, unsigned c)
 {
     BCM2835DMAChan *ch = &s->chan[c];
-    uint32_t data, xlen, ylen;
+    uint32_t data, xlen, xlen_td, ylen;
     int16_t dst_stride, src_stride;
 
     if (!(s->enable & (1 << c))) {
@@ -72,13 +72,13 @@ static void bcm2835_dma_update(BCM2835DMAState *s, unsigned c)
 
         if (ch->ti & BCM2708_DMA_TDMODE) {
             /* 2D transfer mode */
-            ylen = (ch->txfr_len >> 16) & 0x3fff;
-            xlen = ch->txfr_len & 0xffff;
+            ylen = ((ch->txfr_len >> 16) & 0x3fff) + 1;
+            xlen_td = xlen = ch->txfr_len & 0xffff;
             dst_stride = ch->stride >> 16;
             src_stride = ch->stride & 0xffff;
         } else {
             ylen = 1;
-            xlen = ch->txfr_len;
+            xlen_td = xlen = ch->txfr_len;
             dst_stride = 0;
             src_stride = 0;
         }
@@ -117,6 +117,7 @@ static void bcm2835_dma_update(BCM2835DMAState *s, unsigned c)
             if (--ylen != 0) {
                 ch->source_ad += src_stride;
                 ch->dest_ad += dst_stride;
+                xlen = xlen_td;
             }
         }
         ch->cs |= BCM2708_DMA_END;
-- 
2.16.4