hw/scsi/esp-pci: set DMA_STAT_BCMBLT when BLAST command issued

Even though the BLAST command isn't fully implemented in QEMU, the DMA_STAT_BCMBLT
bit should be set after the command has been issued to indicate that the command
has completed.

This fixes an issue with the DC390 DOS driver which issues the BLAST command as
part of its normal error recovery routine at startup, and otherwise sits in a
tight loop waiting for DMA_STAT_BCMBLT to be set before continuing.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Message-ID: <20240112131529.515642-5-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
(cherry picked from commit c2d7de5)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/scsi/esp-pci.c

@@ -124,6 +124,7 @@ static void esp_pci_handle_blast(PCIESPState *pci, uint32_t val)
 {
     trace_esp_pci_dma_blast(val);
     qemu_log_mask(LOG_UNIMP, "am53c974: cmd BLAST not implemented\n");
+    pci->dma_regs[DMA_STAT] |= DMA_STAT_BCMBLT;
 }
 
 static void esp_pci_handle_abort(PCIESPState *pci, uint32_t val)