[PATCH 74/88] esp.c: handle non-DMA FIFO writes used to terminate DMA commands

[Mark Cave-Ayland]

Certain versions of MacOS send the first 5 bytes of the CDB using DMA and then
send the last byte of the CDB by writing to the FIFO. Update the non-DMA state
machine to detect the end of the CDB and execute the SCSI command using similar
logic as that which already exists for transferring the remainder of the CDB
using the ESP TI command.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/scsi/esp.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index f9d848171f..aa7dec71e3 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -787,6 +787,16 @@ static void esp_do_nodma(ESPState *s)
             }
             break;
 
+        case CMD_SEL | CMD_DMA:
+        case CMD_SELATN | CMD_DMA:
+            /* Handle when DMA transfer is terminated by non-DMA FIFO write */
+            if (esp_cdb_length(s) && esp_cdb_length(s) ==
+                fifo8_num_used(&s->cmdfifo) - s->cmdfifo_cdb_offset) {
+                    /* Command has been received */
+                    do_cmd(s);
+            }
+            break;
+
         case CMD_SEL:
         case CMD_SELATN:
             /* FIFO already contain entire CDB */
-- 
2.39.2