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[64/88] esp.c: don't raise INTR_BS interrupt in DATA IN phase until TI command issued

Message ID 20240112125420.514425-65-mark.cave-ayland@ilande.co.uk
State New
Headers show
Series esp: rework ESP emulation to use a SCSI phase-based state machine | expand

Commit Message

Mark Cave-Ayland Jan. 12, 2024, 12:53 p.m. UTC
In the case where a SCSI command with a DATA IN phase has been issued, the host
may preload the FIFO with unaligned bytes before issuing the main DMA transfer.

When accumulating data in the FIFO don't raise the INTR_BS interrupt until the
TI command is issued, otherwise the unexpected interrupt can confuse the host.
In particular this is needed to prevent the MacOS Disk Utility from failing
when switching non-DMA transfers to use esp_do_nodma().

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

Patch

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index bcebd00831..dd6bf6f033 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -786,6 +786,11 @@  static void esp_do_nodma(ESPState *s)
             return;
         }
 
+        /* If preloading the FIFO, defer until TI command issued */
+        if (s->rregs[ESP_CMD] != CMD_TI) {
+            return;
+        }
+
         s->rregs[ESP_RINTR] |= INTR_BS;
         esp_raise_irq(s);
         break;