summary refs log tree commit diff stats
path: root/hw/scsi/esp.c
diff options
context:
space:
mode:
Diffstat (limited to 'hw/scsi/esp.c')
-rw-r--r--hw/scsi/esp.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index ec9fcbeddf..1c7bad8fc0 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -631,7 +631,9 @@ static void esp_do_dma(ESPState *s)
         switch (s->rregs[ESP_CMD]) {
         case CMD_TI | CMD_DMA:
             if (s->dma_memory_write) {
-                s->dma_memory_write(s->dma_opaque, s->async_buf, len);
+                if (len) {
+                    s->dma_memory_write(s->dma_opaque, s->async_buf, len);
+                }
             } else {
                 /* Copy device data to FIFO */
                 len = MIN(len, fifo8_num_free(&s->fifo));
@@ -681,6 +683,7 @@ static void esp_do_dma(ESPState *s)
                 buf[0] = s->status;
 
                 if (s->dma_memory_write) {
+                    /* Length already non-zero */
                     s->dma_memory_write(s->dma_opaque, buf, len);
                 } else {
                     esp_fifo_push_buf(s, buf, len);
@@ -715,6 +718,7 @@ static void esp_do_dma(ESPState *s)
                 buf[0] = 0;
 
                 if (s->dma_memory_write) {
+                    /* Length already non-zero */
                     s->dma_memory_write(s->dma_opaque, buf, len);
                 } else {
                     esp_fifo_push_buf(s, buf, len);