Rather than wait for the FIFO to fill up before calling the PDMA callback, push
that logic directly into the from_device logic in do_dma_pdma_cb().

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: <20240112125420.514425-23-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/scsi/esp.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 06be9f2e74..d80a38daa0 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -625,14 +625,14 @@ static void do_dma_pdma_cb(ESPState *s)
 
         return;
     } else {
-        if (s->async_len == 0) {
+        if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
             /* Defer until the scsi layer has completed */
             scsi_req_continue(s->current_req);
             s->data_in_ready = false;
             return;
         }
 
-        if (esp_get_tc(s) == 0) {
+        if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
             esp_lower_drq(s);
             esp_dma_done(s);
         }
@@ -1419,9 +1419,7 @@ static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
         val = (val << 8) | esp_pdma_read(s);
         break;
     }
-    if (fifo8_num_used(&s->fifo) < 2) {
-        esp_pdma_cb(s);
-    }
+    esp_pdma_cb(s);
     return val;
 }
 
-- 
2.39.2