[PATCH 08/25] esp: apply transfer length adjustment when STC is zero at TC load time

[Mark Cave-Ayland]

Perform the length adjustment whereby a value of 0 in the STC represents
a transfer length of 0x10000 at the point where the TC is loaded at the
start of a DMA command rather than just when a TI (Transfer Information)
command is executed. This better matches the description as given in the
datasheet.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/scsi/esp.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index c716a97847..f38b4a2ecd 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -564,9 +564,6 @@ static void handle_ti(ESPState *s)
     }
 
     dmalen = esp_get_tc(s);
-    if (dmalen == 0) {
-        dmalen = 0x10000;
-    }
     s->dma_counter = dmalen;
 
     if (s->do_cmd) {
@@ -701,7 +698,11 @@ void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t 
val)
         if (val & CMD_DMA) {
             s->dma = 1;
             /* Reload DMA counter.  */
-            esp_set_tc(s, esp_get_stc(s));
+            if (esp_get_stc(s) == 0) {
+                esp_set_tc(s, 0x10000);
+            } else {
+                esp_set_tc(s, esp_get_stc(s));
+            }
         } else {
             s->dma = 0;
         }
-- 
2.20.1