After a reset ESP_TCHI should contain the unique ID of the chip. This value will be overwritten with the current tranfer count if the transfer count has previously been set. The code never checks if the transfer count has been set, so the unique ID will always be overwritten if the driver sends a DMA NOP after reset.
Signed-off-by: Hannes Reinecke <h...@suse.de> --- hw/scsi/esp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 5ab44d8..9798180 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -454,7 +454,9 @@ void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val) /* Reload DMA counter. */ s->rregs[ESP_TCLO] = s->wregs[ESP_TCLO]; s->rregs[ESP_TCMID] = s->wregs[ESP_TCMID]; - s->rregs[ESP_TCHI] = s->wregs[ESP_TCHI]; + if (s->wregs[ESP_TCHI]) { + s->rregs[ESP_TCHI] = s->wregs[ESP_TCHI]; + } } else { s->dma = 0; } -- 1.7.12.4