esp.c: move write_response() non-DMA logic to esp_do_nodma()

This moves the remaining non-DMA STATUS and MESSAGE IN phase logic from
write_response() to esp_do_nodma(). Note that we can also now drop the extra
fifo_reset() which is no longer required.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Helge Deller <deller@gmx.de>
Tested-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20240112125420.514425-69-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

hw/scsi/esp.c

@@ -392,20 +392,12 @@ static void handle_satn_stop(ESPState *s)
 
 static void write_response(ESPState *s)
 {
-    uint8_t buf[2];
-
     trace_esp_write_response(s->status);
 
     if (s->dma) {
         esp_do_dma(s);
     } else {
-        buf[0] = s->status;
-        buf[1] = 0;
-
-        fifo8_reset(&s->fifo);
-        fifo8_push_all(&s->fifo, buf, 2);
-        s->rregs[ESP_RFLAGS] = 2;
-        esp_raise_irq(s);
+        esp_do_nodma(s);
     }
 }
 
@@ -815,6 +807,28 @@ static void esp_do_nodma(ESPState *s)
         s->rregs[ESP_RINTR] |= INTR_BS;
         esp_raise_irq(s);
         break;
+
+    case STAT_ST:
+        switch (s->rregs[ESP_CMD]) {
+        case CMD_ICCS:
+            fifo8_push(&s->fifo, s->status);
+            esp_set_phase(s, STAT_MI);
+
+            /* Process any message in phase data */
+            esp_do_nodma(s);
+            break;
+        }
+        break;
+
+    case STAT_MI:
+        switch (s->rregs[ESP_CMD]) {
+        case CMD_ICCS:
+            fifo8_push(&s->fifo, 0);
+
+            esp_raise_irq(s);
+            break;
+        }
+        break;
     }
 }