esp.c: ensure that STAT_INT is cleared when reading ESP_RINTR

Both esp_raise_irq() and esp_lower_irq() check the STAT_INT bit in ESP_RSTAT
to ensure that the IRQ is raised or lowered if its state changes. When reading
ESP_RINTR, esp_lower_irq() was being called *after* ESP_RSTAT had been
cleared meaning that STAT_INT was already clear, and so if STAT_INT was
asserted beforehand then the esp_lower_irq() would have no effect.

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: <20240112125420.514425-71-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 6c6241798566d4a5dfc2d4009a655e10d5505259..604fb9235d4b88424cc9e130e9db0d24d660137f 100644 (file)
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -1127,6 +1127,7 @@ uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
          */
         val = s->rregs[ESP_RINTR];
         s->rregs[ESP_RINTR] = 0;
+        esp_lower_irq(s);
         s->rregs[ESP_RSTAT] &= ~STAT_TC;
         /*
          * According to the datasheet ESP_RSEQ should be cleared, but as the
@@ -1137,7 +1138,6 @@ uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
          *
          * s->rregs[ESP_RSEQ] = SEQ_0;
          */
-        esp_lower_irq(s);
         break;
     case ESP_TCHI:
         /* Return the unique id if the value has never been written */